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Pol D, Baiano MA, Černý D, Novas FE, Cerda IA, Pittman M. A new abelisaurid dinosaur from the end Cretaceous of Patagonia and evolutionary rates among the Ceratosauria. Cladistics 2024; 40:307-356. [PMID: 38771085 DOI: 10.1111/cla.12583] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2024] [Revised: 04/24/2024] [Accepted: 04/24/2024] [Indexed: 05/22/2024] Open
Abstract
Gondwanan dinosaur faunae during the 20 Myr preceding the Cretaceous-Palaeogene (K/Pg) extinction included several lineages that were absent or poorly represented in Laurasian landmasses. Among these, the South American fossil record contains diverse abelisaurids, arguably the most successful groups of carnivorous dinosaurs from Gondwana in the Cretaceous, reaching their highest diversity towards the end of this period. Here we describe Koleken inakayali gen. et sp. n., a new abelisaurid from the La Colonia Formation (Maastrichtian, Upper Cretaceous) of Patagonia. Koleken inakayali is known from several skull bones, an almost complete dorsal series, complete sacrum, several caudal vertebrae, pelvic girdle and almost complete hind limbs. The new abelisaurid shows a unique set of features in the skull and several anatomical differences from Carnotaurus sastrei (the only other abelisaurid known from the La Colonia Formation). Koleken inakayali is retrieved as a brachyrostran abelisaurid, clustered with other South American abelisaurids from the latest Cretaceous (Campanian-Maastrichtian), such as Aucasaurus, Niebla and Carnotaurus. Leveraging our phylogeny estimates, we explore rates of morphological evolution across ceratosaurian lineages, finding them to be particularly high for elaphrosaurine noasaurids and around the base of Abelisauridae, before the Early Cretaceous radiation of the latter clade. The Noasauridae and their sister clade show contrasting patterns of morphological evolution, with noasaurids undergoing an early phase of accelerated evolution of the axial and hind limb skeleton in the Jurassic, and the abelisaurids exhibiting sustained high rates of cranial evolution during the Early Cretaceous. These results provide much needed context for the evolutionary dynamics of ceratosaurian theropods, contributing to broader understanding of macroevolutionary patterns across dinosaurs.
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Affiliation(s)
- Diego Pol
- Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Mattia Antonio Baiano
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
- Área Laboratorio e Investigación, Museo Municipal Ernesto Bachmann, Villa El Chocón, Neuquén, Argentina
- Universidad Nacional de Río Negro (UNRN), General Roca, Río Negro, Argentina
| | - David Černý
- Department of the Geophysical Sciences, University of Chicago, Chicago, IL, USA
| | - Fernando E Novas
- Museo Argentino de Ciencias Naturales Bernardino Rivadavia, Buenos Aires, Argentina
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
| | - Ignacio A Cerda
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET), Buenos Aires, Argentina
- Universidad Nacional de Río Negro (UNRN), General Roca, Río Negro, Argentina
- Instituto de Investigación en Paleobiología y Geología (IIPG), General Roca, Río Negro, Argentina
- Museo Provincial Carlos Ameghino, Cipolletti, Río Negro, Argentina
| | - Michael Pittman
- School of Life Sciences, The Chinese University of Hong Kong, Shatin, Hong Kong SAR, China
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Bishop PJ, Pierce SE. The fossil record of appendicular muscle evolution in Synapsida on the line to mammals: Part II-Hindlimb. Anat Rec (Hoboken) 2024; 307:1826-1896. [PMID: 37727023 DOI: 10.1002/ar.25310] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2023] [Revised: 07/15/2023] [Accepted: 08/08/2023] [Indexed: 09/21/2023]
Abstract
This paper is the second in a two-part series that charts the evolution of appendicular musculature along the mammalian stem lineage, drawing upon the exceptional fossil record of extinct synapsids. Here, attention is focused on muscles of the hindlimb. Although the hindlimb skeleton did not undergo as marked a transformation on the line to mammals as did the forelimb skeleton, the anatomy of extant tetrapods indicates that major changes to musculature have nonetheless occurred. To better understand these changes, this study surveyed the osteological evidence for muscular attachments in extinct mammalian and nonmammalian synapsids, two extinct amniote outgroups, and a large selection of extant mammals, saurians, and salamanders. Observations were integrated into an explicit phylogenetic framework, comprising 80 character-state complexes covering all muscles crossing the hip, knee, and ankle joints. These were coded for 33 operational taxonomic units spanning >330 Ma of tetrapod evolution, and ancestral state reconstruction was used to evaluate the sequence of muscular evolution along the stem lineage from Amniota to Theria. The evolutionary history of mammalian hindlimb musculature was complex, nonlinear, and protracted, with several instances of convergence and pulses of anatomical transformation that continued well into the crown group. Numerous traits typically regarded as characteristically "mammalian" have much greater antiquity than previously recognized, and for some traits, most synapsids are probably more reflective of the ancestral amniote condition than are extant saurians. More broadly, this study highlights the utility of the fossil record in interpreting the evolutionary appearance of distinctive anatomies.
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Affiliation(s)
- Peter J Bishop
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
- Geosciences Program, Queensland Museum, Brisbane, Queensland, Australia
| | - Stephanie E Pierce
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, Massachusetts, USA
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3
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Nesbitt SJ, Chatterjee S. The osteology of Shuvosaurus inexpectatus, a shuvosaurid pseudosuchian from the Upper Triassic Post Quarry, Dockum Group of Texas, USA. Anat Rec (Hoboken) 2024; 307:1175-1238. [PMID: 38258540 DOI: 10.1002/ar.25376] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2023] [Revised: 12/18/2023] [Accepted: 12/21/2023] [Indexed: 01/24/2024]
Abstract
A vast array of pseudosuchian body plans evolved during the diversification of the group in the Triassic Period, but few can compare to the toothless, long-necked, and bipedal shuvosaurids. Members of this clade possess theropod-like character states mapped on top of more plesiomorphic pseudosuchian character states, complicating our understanding of the evolutionary history of the skeleton. One taxon in this clade, Shuvosaurus inexpectatus has been assigned to various theropod dinosaur groups based on a partial skull and referred material and its postcranium was assigned to a different taxon in Pseudosuchia. After the discovery of a skeleton of a shuvosaurid with a Shuvosaurus-like skull and a pseudosuchian postcranial skeleton, it became clear Shuvosaurus inexpectatus was a pseudosuchian. Nevertheless, a number of questions have arisen about what skeletal elements belonged to Shuvosaurus inexpectatus, the identification of skull bones, and the resulting implication for pseudosuchian evolution. Here, we detail the anatomy of the skeleton Shuvosaurus inexpectatus through a critical lens, parse out the bones that belong to the taxon or those that clearly do not or may not belong to the taxon, rediagnose the taxon based on these revisions, and compare the taxon to other archosaurs. We find that Shuvosaurus inexpectatus possesses similar anatomy to other shuvosaurids but parts of the skeleton of the taxon clarifies the anatomy of the group given that they are preserved in Shuvosaurus inexpectatus but not in others. Shuvosaurus inexpectatus is represented by at least 14 individuals from the West Texas Post Quarry (Adamanian holochronozone) and all Shuvosaurus inexpectatus skeletal material from the locality pertains to skeletally immature individuals. All of the skeletons are missing most of the neural arches, ribs, and most of the forelimb. We only recognize Shuvosaurus inexpectatus from the Post Quarry and all other material assigned to the taxon previously is better assigned to the broader group Shuvosauridae.
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Affiliation(s)
- Sterling J Nesbitt
- Department of Geosciences, Virginia Tech, Blacksburg, Virginia, USA
- Museum of Texas Tech University, Lubbock, Texas, USA
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Xu L, Wang M, Chen R, Dong L, Lin M, Xu X, Tang J, You H, Zhou G, Wang L, He W, Li Y, Zhang C, Zhou Z. A new avialan theropod from an emerging Jurassic terrestrial fauna. Nature 2023; 621:336-343. [PMID: 37674081 DOI: 10.1038/s41586-023-06513-7] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2023] [Accepted: 08/02/2023] [Indexed: 09/08/2023]
Abstract
Birds are descended from non-avialan theropod dinosaurs of the Late Jurassic period, but the earliest phase of this evolutionary process remains unclear owing to the exceedingly sparse and spatio-temporally restricted fossil record1-5. Information about the early-diverging species along the avialan line is crucial to understand the evolution of the characteristic bird bauplan, and to reconcile phylogenetic controversies over the origin of birds3,4. Here we describe one of the stratigraphically youngest and geographically southernmost Jurassic avialans, Fujianvenator prodigiosus gen. et sp. nov., from the Tithonian age of China. This specimen exhibits an unusual set of morphological features that are shared with other stem avialans, troodontids and dromaeosaurids, showing the effects of evolutionary mosaicism in deep avialan phylogeny. F. prodigiosus is distinct from all other Mesozoic avialan and non-avialan theropods in having a particularly elongated hindlimb, suggestive of a terrestrial or wading lifestyle-in contrast with other early avialans, which exhibit morphological adaptations to arboreal or aerial environments. During our fieldwork in Zhenghe where F. prodigiosus was found, we discovered a diverse assemblage of vertebrates dominated by aquatic and semi-aquatic species, including teleosts, testudines and choristoderes. Using in situ radioisotopic dating and stratigraphic surveys, we were able to date the fossil-containing horizons in this locality-which we name the Zhenghe Fauna-to 148-150 million years ago. The diversity of the Zhenghe Fauna and its precise chronological framework will provide key insights into terrestrial ecosystems of the Late Jurassic.
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Affiliation(s)
- Liming Xu
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Min Wang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China.
| | - Runsheng Chen
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Liping Dong
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Min Lin
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- Centre for Vertebrate Evolutionary Biology, Yunnan University, Kunming, China
- Paleontological Museum of Liaoning, Shenyang Normal University, Shenyang, China
| | - Jianrong Tang
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Hailu You
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Guowu Zhou
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Linchang Wang
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Wenxing He
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Yujuan Li
- Fujian Institute of Geological Survey, Fuzhou, China
| | - Chi Zhang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Zhonghe Zhou
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
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Gouvêa DY, Brigandt I. Against unifying homology concepts: Redirecting the debate. J Morphol 2023; 284:e21599. [PMID: 37313763 DOI: 10.1002/jmor.21599] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/27/2022] [Revised: 04/29/2023] [Accepted: 05/06/2023] [Indexed: 06/15/2023]
Abstract
The term "homology" is persistently polysemous, defying the expectation that extensive scientific research should yield semantic stability. A common response has been to seek a unification of various prominent definitions. This paper proposes an alternative strategy, based on the insight that scientific concepts function as tools for research: When analyzing various conceptualizations of homology, we should preserve those distinguishing features that support particular research goals. We illustrate the fruitfulness of our strategy by application to two cases. First, we revisit Lankester's celebrated evolutionary reappraisal of homology and argue that his analysis has been distorted by assimilation to modern agendas. His "homogeny" does not mean the same thing as modern evolutionary "homology," and his "homoplasy" is no mere antonym. Instead, Lankester uses both new terms to pose a question that remains strikingly relevant-how do mechanistic and historical causes of morphological resemblance interact? Second, we examine the puzzle of avian digit homology, which exemplifies disciplinary differences in homology conceptualization and assessment. Recent progress has been fueled by the development of new tools within the relevant disciplines (paleontology and developmental biology) and especially by increasing interdisciplinary cooperation. Conceptual unification has played very little role in this work, which instead seeks concrete evolutionary scenarios that integrate all the available evidence. Together these cases indicate the complex relationship between concepts and other tools in homology research.
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Affiliation(s)
- Devin Y Gouvêa
- Department of Philosophy, College of the Holy Cross, Worcester, Massachusetts, USA
| | - Ingo Brigandt
- Department of Philosophy, University of Alberta, Edmonton, Canada
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Chapelle KEJ, Botha J, Choiniere JN. Osteohistology reveals the smallest adult Jurassic sauropodomorph. ROYAL SOCIETY OPEN SCIENCE 2023; 10:221565. [PMID: 37325591 PMCID: PMC10265025 DOI: 10.1098/rsos.221565] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Accepted: 04/26/2023] [Indexed: 06/17/2023]
Abstract
The earliest sauropodomorphs were small omnivores (less than 10 kg) that first appeared in the Carnian. By the Hettangian, early branching sauropodomorphs (EBSMs) were globally distributed, had variable postures, and some attained large body masses (greater than 10 tonnes). Small-bodied EBSMs like Massospondylus carinatus (less than 550 kg) persist at least until the Pliensbachian at nearly all dinosaur-bearing localities worldwide but are comparatively low in alpha diversity. One potential reason for this is competition with other similarly sized contemporary amniotes, including Triassic gomphodont cynodonts, Jurassic early branching ornithischians, herbivorous theropods and potentially early crocodylomorphs. Today's herbivorous mammals show a range of body size classes (less than 10 g to 7 tonnes), with multiple species of small herbivorous mammals (less than 100 kg) frequently co-occurring. Comparatively, our understanding of the phylogenetic distribution of body mass in Early Jurassic strata, and its explanatory power for the lower thresholds of body mass in EBSMs, needs more data. We osteohistologically sectioned a small humerus, BP/1/4732, from the upper Elliot Formation of South Africa. Its comparative morphology and osteohistology show that it represents a skeletally mature individual of a new sauropodomorph taxon with a body mass of approx. 75.35 kg. This makes it one of the smallest known sauropodomorph taxa, and the smallest ever reported from a Jurassic stratum.
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Affiliation(s)
- Kimberley E. J. Chapelle
- Division of Paleontology, American Museum of Natural History, Central Park West at 79th Street, New York, NY 10024-5192, USA
- Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2000, South Africa
| | - Jennifer Botha
- Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2000, South Africa
- GENUS Centre of Excellence in Palaeosciences, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2000, South Africa
| | - Jonah N. Choiniere
- Evolutionary Studies Institute, University of the Witwatersrand, 1 Jan Smuts Avenue, Johannesburg 2000, South Africa
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7
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Salem BS, Lamanna MC, O'Connor PM, El-Qot GM, Shaker F, Thabet WA, El-Sayed S, Sallam HM. First definitive record of Abelisauridae (Theropoda: Ceratosauria) from the Cretaceous Bahariya Formation, Bahariya Oasis, Western Desert of Egypt. ROYAL SOCIETY OPEN SCIENCE 2022; 9:220106. [PMID: 35706658 PMCID: PMC9174736 DOI: 10.1098/rsos.220106] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 05/11/2022] [Indexed: 05/03/2023]
Abstract
Numerous non-avian theropod dinosaur fossils have been reported from the Upper Cretaceous (Cenomanian) Bahariya Formation, Bahariya Oasis, Western Desert of Egypt, but unambiguous materials of Abelisauridae have yet to be documented. Here we report Mansoura University Vertebrate Paleontology Center (MUVP) specimen 477, an isolated, well-preserved tenth cervical vertebra of a medium-sized abelisaurid from the Bahariya Formation. The new vertebra shows affinities with those of other Upper Cretaceous abelisaurids from Madagascar and South America, such as Majungasaurus crenatissimus, Carnotaurus sastrei, Viavenator exxoni and a generically indeterminate Patagonian specimen (Museo Padre Molina specimen 99). Phylogenetic analysis recovers the Bahariya form within Abelisauridae, either in a polytomy of all included abelisaurids (strict consensus tree) or as an early branching member of the otherwise South American clade Brachyrostra (50% majority rule consensus tree). MUVP 477, therefore, represents the first confirmed abelisaurid fossil from the Bahariya Formation and the oldest definitive record of the clade from Egypt and northeastern Africa more generally. The new vertebra demonstrates the wide geographical distribution of Abelisauridae across North Africa during the middle Cretaceous and augments the already extraordinarily diverse large-bodied theropod assemblage of the Bahariya Formation, a record that also includes representatives of Spinosauridae, Carcharodontosauridae and Bahariasauridae.
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Affiliation(s)
- Belal S. Salem
- Department of Geology, Faculty of Science, Benha University, Benha, Egypt
- Mansoura University Vertebrate Paleontology Center (MUVP), Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt
- Department of Biological Sciences, Ohio University, 228 Irvine Hall, Athens, OH, USA
- Ohio Center for Ecological and Evolutionary Studies, Ohio University, Athens, OH, USA
| | - Matthew C. Lamanna
- Section of Vertebrate Paleontology, Carnegie Museum of Natural History, Pittsburgh, PA, USA
| | - Patrick M. O'Connor
- Ohio Center for Ecological and Evolutionary Studies, Ohio University, Athens, OH, USA
- Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, Ohio University, Athens, OH, USA
| | - Gamal M. El-Qot
- Department of Geology, Faculty of Science, Benha University, Benha, Egypt
| | - Fatma Shaker
- Department of Geology, Faculty of Science, Benha University, Benha, Egypt
| | | | - Sanaa El-Sayed
- Mansoura University Vertebrate Paleontology Center (MUVP), Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt
- Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI, USA
| | - Hesham M. Sallam
- Mansoura University Vertebrate Paleontology Center (MUVP), Department of Geology, Faculty of Science, Mansoura University, Mansoura, Egypt
- Institute of Global Health and Human Ecology (I-GHHE), School of Sciences and Engineering, American University in Cairo, New Cairo, Egypt
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Cerroni MA, Canale JI, Novas FE, Paulina‐Carabajal A. An exceptional neurovascular system in abelisaurid theropod skull: New evidence from Skorpiovenator bustingorryi. J Anat 2022; 240:612-626. [PMID: 32569442 PMCID: PMC8930818 DOI: 10.1111/joa.13258] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2020] [Revised: 05/03/2020] [Accepted: 05/26/2020] [Indexed: 11/29/2022] Open
Abstract
Abelisaurids were one of the most successful theropod dinosaurs during Cretaceous times. They are featured by numerous derived skull traits, such as heavily ornamented bones, short and tall snout, and a strongly thickened cranial roof. Furthermore, nasals are distinctive on having two distinct nasal patterns: strongly transversely convex and heavily sculptured (e.g., Carnotaurus), and transversely concave, with marked bilateral crests and poorly sculptured surfaces (e.g., Rugops). Independently of the pattern, some abelisaurid nasals (e.g., Rugops) show a distinctive row of large foramina on the dorsal surface, which were in general associated to skin structures (scales). Skorpiovenator bustingorryi is a derived abelisaurid coming from the upper Cretaceous beds of northwestern Patagonia, represented by an almost complete skeleton including a well-preserved skull. Particularly, the skull of Skorpiovenator shows nasal bones characterized by being transversely concave, rimmed by lateral crests and with a conspicuous row of foramina on the dorsal surface. But more interesting is that the skull roof also exhibits a row of large foramina that seem to be continuous with the previous nasal foramina. CT scans made on the skull corroborates a novel feature within theropods: the nasal foramina on the external surface are linked to an internal canal that runs across the nasal bones. We compared this feature with CT scans of Carnotaurus and revealed that it also possess an internal system as in Skorpiovenator, but being notably smaller. The symmetry and disposition of the foramina in the nasal and skull roof bones of Skorpiovenator would indicate a neurovascular correlate (i.e., blood vessels and nerves), probably to the lateral nasal and supraorbital vessels and the trigeminal nerve. The biological significance of such neurovascular system can be conjectured from several hypotheses. A possible one involves an enhanced blood volume in these bones linked to a zone of thermal exchange, which may help avoid overheat of encephalic tissues. Another plausible hypothesis takes into account the presence of display skin structures in which blood volume nourished the mineralized skin, which would have a role in intraspecific communication. However, other more speculative explanations should not be discarded such as a correlation with integumentary sensory organs.
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Affiliation(s)
- Mauricio A. Cerroni
- Laboratorio de Anatomía Comparada y Evolución de los VertebradosMuseo Argentino de Ciencias Naturales “Bernardino Rivadavia”, CONICETBuenos AiresArgentina
| | - Juan I. Canale
- Área Laboratorio e InvestigaciónMuseo Paleontológico “Ernesto Bachmann”, CONICETVilla El Chocón NeuquénArgentina
| | - Fernando E. Novas
- Laboratorio de Anatomía Comparada y Evolución de los VertebradosMuseo Argentino de Ciencias Naturales “Bernardino Rivadavia”, CONICETBuenos AiresArgentina
| | - Ariana Paulina‐Carabajal
- Instituto de Investigaciones en Biodiversidad y Medioambiente (CONICET‐Universidad Nacional del Comahue), CONICETSan Carlos de BarilocheArgentina
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9
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Bestwick J, Jones AS, Nesbitt SJ, Lautenschlager S, Rayfield EJ, Cuff AR, Button DJ, Barrett PM, Porro LB, Butler RJ. Cranial functional morphology of the pseudosuchian Effigia and implications for its ecological role in the Triassic. Anat Rec (Hoboken) 2021; 305:2435-2462. [PMID: 34841701 DOI: 10.1002/ar.24827] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2021] [Revised: 09/10/2021] [Accepted: 10/07/2021] [Indexed: 11/06/2022]
Abstract
Pseudosuchians, archosaurian reptiles more closely related to crocodylians than to birds, exhibited high morphological diversity during the Triassic with numerous examples of morphological convergence described between Triassic pseudosuchians and post-Triassic dinosaurs. One example is the shuvosaurid Effigia okeeffeae which exhibits an "ostrich-like" bauplan comprising a gracile skeleton with edentulous jaws and large orbits, similar to ornithomimid dinosaurs and extant palaeognaths. This bauplan is regarded as an adaptation for herbivory, but this hypothesis assumes morphological convergence confers functional convergence, and has received little explicit testing. Here, we restore the skull morphology of Effigia, perform myological reconstructions, and apply finite element analysis to quantitatively investigate skull function. We also perform finite element analysis on the crania of the ornithomimid dinosaur Ornithomimus edmontonicus, the extant palaeognath Struthio camelus and the extant pseudosuchian Alligator mississippiensis to assess the degree of functional convergence with a taxon that exhibit "ostrich-like" bauplans and its closest extant relatives. We find that Effigia possesses a mosaic of mechanically strong and weak features, including a weak mandible that likely restricted feeding to the anterior portion of the jaws. We find limited functional convergence with Ornithomimus and Struthio and limited evidence of phylogenetic constraints with extant pseudosuchians. We infer that Effigia was a specialist herbivore that likely fed on softer plant material, a niche unique among the study taxa and potentially among contemporaneous Triassic herbivores. This study increases the known functional diversity of pseudosuchians and highlights that superficial morphological similarity between unrelated taxa does not always imply functional and ecological convergence.
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Affiliation(s)
- Jordan Bestwick
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | - Andrew S Jones
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | | | - Stephan Lautenschlager
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
| | | | - Andrew R Cuff
- Centre for Anatomical and Human Sciences, Hull York Medical School, University of York, York, UK
| | - David J Button
- Department of Earth Sciences, The Natural History Museum, London, UK
| | - Paul M Barrett
- Department of Earth Sciences, The Natural History Museum, London, UK
| | - Laura B Porro
- Centre for Integrative Anatomy, Department of Cell and Developmental Biology, University College London, London, UK
| | - Richard J Butler
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, UK
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10
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de Souza GA, Soares MB, Weinschütz LC, Wilner E, Lopes RT, de Araújo OMO, Kellner AWA. The first edentulous ceratosaur from South America. Sci Rep 2021; 11:22281. [PMID: 34795306 PMCID: PMC8602317 DOI: 10.1038/s41598-021-01312-4] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2021] [Accepted: 10/18/2021] [Indexed: 11/09/2022] Open
Abstract
The recognition of ontogenetic edentulism in the Jurassic noasaurid Limusaurus inextricabilis shed new light on the dietary diversity within Ceratosauria, a stem lineage of non-avian theropod dinosaurs known for peculiar craniomandibular adaptations. Until now, edentulism in Ceratosauria was exclusive to adult individuals of Limusaurus. Here, an exceptionally complete skeleton of a new toothless ceratosaur, Berthasaura leopoldinae gen. et sp. nov., is described from the Cretaceous aeolian sandstones of the Bauru Basin, Southern Brazil. The specimen resembles adult individuals of Limusaurus by the absence of teeth but based on the unfused condition of several elements (e.g., skull, vertebral column) it clearly represents an ontogenetically immature individual, indicating that it might never have had teeth. The phylogenetic analysis performed here has nested Berthasaura leopoldinae as an early-divergent Noasauridae, not closely related to Limusaurus. It represents the most complete non-avian theropod from the Brazilian Cretaceous and preserves the most complete noasaurid axial series known so far. Moreover, the new taxon exhibits many novel osteological features, uncommon in non-avian theropods, and unprecedented even among South American ceratosaurs. These include not only toothless jaws but also a premaxilla with cutting occlusal edge, and a slightly downturned rostral tip. This indicate that B. leopoldinae unlikely had the same diet as other ceratosaurs, most being regarded as carnivorous. As the ontogenetically more mature specimens of Limusaurus, Berthasaura might have been herbivorous or at least omnivorous, corroborating with an early evolutionary divergence of noasaurids from the ceratosaurian bauplan by disparate feeding modes.
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Affiliation(s)
- Geovane Alves de Souza
- Programa de Pós-graduação em Zoologia (PPGZoo), Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, São Cristóvão, Rio de Janeiro, RJ, 20940-040, Brazil.,Laboratório de Sistemática e Tafonomia de Vertebrados Fósseis (LAPUG), Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, São Cristóvão, Rio de Janeiro, RJ, 20940-040, Brazil
| | - Marina Bento Soares
- Laboratório de Sistemática e Tafonomia de Vertebrados Fósseis (LAPUG), Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, São Cristóvão, Rio de Janeiro, RJ, 20940-040, Brazil
| | - Luiz Carlos Weinschütz
- Centro Paleontológico da Universidade do Contestado (CENPALEO), Universidade do Contestado, Av. Presidente Nereu Ramos, 1071, Jardim Moinho, Mafra, SC, 89.306-076, Brazil
| | - Everton Wilner
- Centro Paleontológico da Universidade do Contestado (CENPALEO), Universidade do Contestado, Av. Presidente Nereu Ramos, 1071, Jardim Moinho, Mafra, SC, 89.306-076, Brazil
| | - Ricardo Tadeu Lopes
- Laboratório de Instrumentação Nuclear (LIN), Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Av. Horácio Macedo, Cidade Universitária, Rio de Janeiro, RJ, 21941-450, Brazil
| | - Olga Maria Oliveira de Araújo
- Laboratório de Instrumentação Nuclear (LIN), Programa de Engenharia Nuclear/COPPE, Universidade Federal do Rio de Janeiro, Av. Horácio Macedo, Cidade Universitária, Rio de Janeiro, RJ, 21941-450, Brazil
| | - Alexander Wilhelm Armin Kellner
- Laboratório de Sistemática e Tafonomia de Vertebrados Fósseis (LAPUG), Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, São Cristóvão, Rio de Janeiro, RJ, 20940-040, Brazil.
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11
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Liao CC, Zanno LE, Wang S, Xu X. Postcranial osteology of Beipiaosaurus inexpectus (Theropoda: Therizinosauria). PLoS One 2021; 16:e0257913. [PMID: 34591927 PMCID: PMC8483305 DOI: 10.1371/journal.pone.0257913] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2021] [Accepted: 09/13/2021] [Indexed: 11/25/2022] Open
Abstract
Beipiaosaurus inexpectus, from the Lower Cretaceous Yixian Formation (Sihetun locality, near Beipiao), Liaoning, China, is a key taxon for understanding the early evolution of therizinosaurians. Since initial publication in 1999, only the cranial elements of this taxon have been described in detail. Here we present a detailed description of the postcranial skeletal anatomy of the holotype specimen of B. inexpectus, including two never before described dorsal vertebrae from the anterior half of the series. Based on these observations, and comparisons with the postcranial skeleton of therizinosaurian taxa named since the most recent diagnosis, we revised the diagnostic features for B. inexpectus adding three new possible autapomorphies (PII-3 shorter than PIII-4, subequal length of the pre- and postacetabular portions of the ilium, and equidimensional pubic peduncle of ilium). Additionally, we also propose three possible synapomorphies for more inclusive taxa (Therizinosauroidea and Therizinosauridae) and discuss implications for evolutionary trends within Therizinosauria. The newly acquired data from the postcranial osteology of the holotype specimen of B. inexpectus sheds light on our understanding of postcranial skeletal evolution and identification of therizinosaurians.
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Affiliation(s)
- Chun-Chi Liao
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Lindsay E. Zanno
- Paleontology, North Carolina Museum of Natural Sciences, Raleigh, North Carolina, United States of America
- Department of Biological Sciences, North Carolina State University, Raleigh, North Carolina, United States of America
| | - Shiying Wang
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
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12
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Griffin CT, Stocker MR, Colleary C, Stefanic CM, Lessner EJ, Riegler M, Formoso K, Koeller K, Nesbitt SJ. Assessing ontogenetic maturity in extinct saurian reptiles. Biol Rev Camb Philos Soc 2020; 96:470-525. [PMID: 33289322 DOI: 10.1111/brv.12666] [Citation(s) in RCA: 40] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 10/09/2020] [Accepted: 10/28/2020] [Indexed: 01/06/2023]
Abstract
Morphology forms the most fundamental level of data in vertebrate palaeontology because it is through interpretations of morphology that taxa are identified, creating the basis for broad evolutionary and palaeobiological hypotheses. Assessing maturity is one of the most basic aspects of morphological interpretation and provides the means to study the evolution of ontogenetic changes, population structure and palaeoecology, life-history strategies, and heterochrony along evolutionary lineages that would otherwise be lost to time. Saurian reptiles (the least-inclusive clade containing Lepidosauria and Archosauria) have remained an incredibly diverse, numerous, and disparate clade through their ~260-million-year history. Because of the great disparity in this group, assessing maturity of saurian reptiles is difficult, fraught with methodological and terminological ambiguity. We compiled a novel database of literature, assembling >900 individual instances of saurian maturity assessment, to examine critically how saurian maturity has been diagnosed. We review the often inexact and inconsistent terminology used in saurian maturity assessment (e.g. 'juvenile', 'mature') and provide routes for better clarity and cross-study coherence. We describe the various methods that have been used to assess maturity in every major saurian group, integrating data from both extant and extinct taxa to give a full account of the current state of the field and providing method-specific pitfalls, best practices, and fruitful directions for future research. We recommend that a new standard subsection, 'Ontogenetic Assessment', be added to the Systematic Palaeontology portions of descriptive studies to provide explicit ontogenetic diagnoses with clear criteria. Because the utility of different ontogenetic criteria is highly subclade dependent among saurians, even for widely used methods (e.g. neurocentral suture fusion), we recommend that phylogenetic context, preferably in the form of a phylogenetic bracket, be used to justify the use of a maturity assessment method. Different methods should be used in conjunction as independent lines of evidence when assessing maturity, instead of an ontogenetic diagnosis resting entirely on a single criterion, which is common in the literature. Critically, there is a need for data from extant taxa with well-represented growth series to be integrated with the fossil record to ground maturity assessments of extinct taxa in well-constrained, empirically tested methods.
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Affiliation(s)
- Christopher T Griffin
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
| | - Michelle R Stocker
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
| | - Caitlin Colleary
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Vertebrate Paleontology, Cleveland Museum of Natural History, 1 Wade Oval Drive, Cleveland, OH, 44106, U.S.A
| | - Candice M Stefanic
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Anatomical Sciences, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, U.S.A
| | - Emily J Lessner
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Pathology and Anatomical Sciences, University of Missouri, 1 Hospital Drive, Columbia, MO, 65212, U.S.A
| | - Mitchell Riegler
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Geological Sciences, University of Florida, 241 Williamson Hall, Gainesville, FL, 32611, U.S.A
| | - Kiersten Formoso
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Earth Sciences, University of Southern California, 3651 Trousdale Pkwy, Los Angeles, CA, 90089, U.S.A
- Dinosaur Institute, Natural History Museum of Los Angeles County, 900 W Exposition Boulevard, Los Angeles, CA, 90007, U.S.A
| | - Krista Koeller
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Biology, University of Florida, 220 Bartram Hall, Gainesville, FL, 32611, U.S.A
| | - Sterling J Nesbitt
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
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13
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Funston GF, Chinzorig T, Tsogtbaatar K, Kobayashi Y, Sullivan C, Currie PJ. A new two-fingered dinosaur sheds light on the radiation of Oviraptorosauria. ROYAL SOCIETY OPEN SCIENCE 2020; 7:201184. [PMID: 33204472 PMCID: PMC7657903 DOI: 10.1098/rsos.201184] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/06/2020] [Accepted: 09/07/2020] [Indexed: 06/11/2023]
Abstract
Late Cretaceous trends in Asian dinosaur diversity are poorly understood, but recent discoveries have documented a radiation of oviraptorosaur theropods in China and Mongolia. However, little work has addressed the factors that facilitated this diversification. A new oviraptorid from the Late Cretaceous of Mongolia sheds light on the evolution of the forelimb, which appears to have played a role in the radiation of oviraptorosaurs. Surprisingly, the reduced arm has only two functional digits, highlighting a previously unrecognized occurrence of digit loss in theropods. Phylogenetic analysis shows that the onset of this reduction coincides with the radiation of heyuannine oviraptorids, following dispersal from southern China into the Gobi region. This suggests expansion into a new niche in the Gobi region, which relied less on the elongate, grasping forelimbs inherited by oviraptorosaurs. Variation in forelimb length and manus morphology provides another example of niche partitioning in oviraptorosaurs, which may have made possible their incredible diversity in the latest Cretaceous of Asia.
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Affiliation(s)
- Gregory F. Funston
- School of GeoSciences, University of Edinburgh, Edinburgh, UK
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
| | - Tsogtbaatar Chinzorig
- Hokkaido University Museum, Hokkaido University, Sapporo, Japan
- Institute of Paleontology, Mongolian Academy of Sciences, Ulaanbaatar, Mongolia
| | | | | | - Corwin Sullivan
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
- Philip J. Currie Dinosaur Museum, Wembley, Alberta, Canada
| | - Philip J. Currie
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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14
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de Souza GA, Soares MB, Brum AS, Zucolotto M, Sayão JM, Weinschütz LC, Kellner AWA. Osteohistology and growth dynamics of the Brazilian noasaurid Vespersaurus paranaensis Langer et al., 2019 (Theropoda: Abelisauroidea). PeerJ 2020; 8:e9771. [PMID: 32983636 PMCID: PMC7500327 DOI: 10.7717/peerj.9771] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2020] [Accepted: 07/30/2020] [Indexed: 12/24/2022] Open
Abstract
Although the knowledge of bone histology of non-avian theropods has advanced considerably in recent decades, data about the bone tissue patterns, growth dynamics and ontogeny of some taxa such as abelisauroids are still limited. Here we describe the bone microstructure and growth dynamics of the Brazilian noasaurine Vespersaurus paranaensis using five femora and six tibiae and quantify the annual growth marks through retrocalculation of missing ones to estimate ontogenetic ages. The femoral series comprises four femoral histological classes (FHC I-IV), varying from two annuli or LAGs to seven LAGs. Femora show that sexual maturity was achieved around the seventh to tenth year of life, whereas the tibiae suggest it was earlier (around three to five years old). Tibiae represent three histological classes (THC I-III) displaying from three to nine LAGs. Two tibiae (THC III) exhibit an external fundamental system indicating that these specimens reached full skeletal size. The heterogeneous maturity observed in Vespersaurus hind limb bones could result from differential allometry scaling between femora and tibiae length with the body length. The predominant parallel-fibered bone matrix suggests that Vespersaurus grew more slowly than most theropods, including other abelisauroids, in a pattern shared with the noasaurines Masiakasaurus knopfleri from Madagascar and CPPLIP 1490 from Brazil. This deviation from the typical theropod growth pattern may be mainly correlated with small body size, but also may related to resource limitation imposed by the arid climate prevailing in southwestern Gondwana during Cretaceous. Moreover, given the ecological and phylogenetic similarities among these taxa, such features would probably be apomorphic within Noasauridae.
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Affiliation(s)
- Geovane Alves de Souza
- Programa de Pós-Graduação em Zoologia (PPGZoo), Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Marina Bento Soares
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Arthur Souza Brum
- Programa de Pós-Graduação em Zoologia (PPGZoo), Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Maria Zucolotto
- Departamento de Geologia e Paleontologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Juliana M Sayão
- Núcleo de Biologia, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Vitória de Santo Antão, Pernambuco, Brazil
| | | | - Alexander W A Kellner
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
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15
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Aranciaga Rolando M, Garcia Marsà J, Novas F. Histology and pneumaticity of Aoniraptor libertatem (Dinosauria, Theropoda), an enigmatic mid-sized megaraptoran from Patagonia. J Anat 2020; 237:741-756. [PMID: 32470191 DOI: 10.1111/joa.13225] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2020] [Revised: 05/04/2020] [Accepted: 05/05/2020] [Indexed: 11/29/2022] Open
Abstract
Aoniraptor libertatem is a mid-sized megaraptoran that comes from the Late Cretaceous (Turonian) Huincul Formation at Río Negro province, Patagonia, Argentina. In this study, we conducted a detailed analysis of pneumaticity of the sacrum and tail of Aoniraptor. This shows a complex structure within these vertebrae, being composed by small diverticulae surrounding large pneumatic canals and a central chamber that opens outside through pleurocoels or pneumatic canals. Further, we carried out a histologic analysis which confirms the pneumatic nature of these anatomical features. Both analyses found that chevrons in Aoniraptor were invaded by pneumaticity, a feature that appears to be unique to this taxon. In addition, a comparative analysis between Aoniraptor and other theropods (e.g. Gualicho and other megaraptorans) was carried out. This resulted in the modification of previous schemes about the evolution of pneumaticity through Theropoda, the finding of some evolutionary pneumatic traits through Megaraptora, and the usefulness of pneumatic traits as a taxonomic tool.
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Affiliation(s)
- Mauro Aranciaga Rolando
- Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Buenos Aires, Argentina.,Museo Municipal de Ciencias Naturales "Carlos Ameghino", Mercedes, Argentina
| | - Jordi Garcia Marsà
- Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Buenos Aires, Argentina
| | - Fernando Novas
- Museo Argentino de Ciencias Naturales 'Bernardino Rivadavia', Consejo Nacional de Investigaciones Científicas y Técnicas - CONICET, Buenos Aires, Argentina
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16
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Forelimb shortening of Carcharodontosauria (Dinosauria: Theropoda): an update on evolutionary anterior micromelias in non-avian theropods. ZOOLOGY 2020; 139:125756. [PMID: 32088525 DOI: 10.1016/j.zool.2020.125756] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2019] [Revised: 02/02/2020] [Accepted: 02/04/2020] [Indexed: 12/25/2022]
Abstract
Evolutionary teratology recognises certain anatomical modifications as developmental anomalies. Within non avian-theropod dinosaurs, the strong forelimb shortening of Tyrannosauridae, Carnotaurinae and Limusaurus - associated with a reduction or loss of autonomy - have been previously diagnosed as evolutionary anterior micromelias. The feature is here examined with Acrocanthosaurus atokensis (Carcharodontosauridae) and Gualicho shinyae (Neovenatoridae). The micromelic diagnosis is confirmed for Acrocanthosaurus, without supplementary malformations. Gualicho is considered as a borderline case, outside of the micromelic spectrum, but shows a total phalangeal loss on digit III. The reduction in the biomechanical range of Acrocanthosaurus' forelimbs was compensated by the skull and jaws as main predatory organs. The same is assumed for Gualicho, but its robust first digit and raptorial claw are to be underlined. Other gigantic-sized and derived representatives of Carcharodontosauridae probably shared the anterior micromelia condition, potentially due to developmental modifications involving differential forelimbs/hindlimbs embryological growth rates, secondarily associated with post-natal growth rates leading to large and gigantic sizes; a converging state with Tyrannosauridae. Nevertheless, whereas developmental growth rates are also considered in the shortened condition of Gualicho, there is no association with post-natal gigantism. Finally, the digit III reduction likely followed the same evolutionary pathways as Tyrannosauridae, potentially involving BMPs, Fgfs and Shh signalling.
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17
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Birch SA, Smith ET, Bell PR. Noasaurids are a component of the Australian 'mid'-Cretaceous theropod fauna. Sci Rep 2020; 10:1428. [PMID: 31996712 PMCID: PMC6989633 DOI: 10.1038/s41598-020-57667-7] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2019] [Accepted: 12/26/2019] [Indexed: 12/12/2022] Open
Abstract
The diversity of Australia's theropod fauna from the 'mid'-Cretaceous (Albian-Cenomanian) is distinctly biased towards the medium-sized megaraptorids, despite the preponderance of abelisauroids in the younger but latitudinally equivalent Patagonian theropod fauna. Here, we present new evidence for the presence of ceratosaurian, and specifically abelisauroid, theropods from the Cenomanian Griman Creek Formation of Lightning Ridge, New South Wales. A partial cervical vertebra is described that bears a mediolaterally concave ventral surface of the centrum delimited by sharp ventrolateral ridges that contact the parapophyses. Among theropods, this feature has been reported only in a cervical vertebra attributed to the noasaurid Noasaurus. We also reappraise evidence recently cited against the ceratosaurian interpretation of a recently described astragalocalcaneum from the upper Barremian-lower Aptian San Remo Member of the upper Strzelecki Group in Victoria. Inclusion of the Lightning Ridge cervical vertebra and Victorian astragalocalcaneum into a revised phylogenetic analysis focused on elucidating ceratosaurian affinities reveals support for placement of both specimens within Noasauridae, which among other characters is diagnosed by the presence of a medial eminence on the ascending process of the astragalus. The Lightning Ridge and Victorian specimens simultaneously represent the first noasaurids reported from Australia and the astragalocalcaneum is considered the earliest known example of a noasaurid in the world to date. The recognition of Australian noasaurids further indicates a more widespread Gondwanan distribution of the clade outside of South America, Madagascar and India consistent with the timing of the fragmentation of the supercontinent.
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Affiliation(s)
- Sienna A Birch
- School of environmental and Rural Science, University of New England, Armidale, NSW, Australia.
| | | | - Phil R Bell
- School of environmental and Rural Science, University of New England, Armidale, NSW, Australia
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18
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Button DJ, Zanno LE. Repeated Evolution of Divergent Modes of Herbivory in Non-avian Dinosaurs. Curr Biol 2020; 30:158-168.e4. [DOI: 10.1016/j.cub.2019.10.050] [Citation(s) in RCA: 20] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Revised: 09/08/2019] [Accepted: 10/25/2019] [Indexed: 01/13/2023]
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19
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Ma W, Brusatte SL, Lü J, Sakamoto M. The skull evolution of oviraptorosaurian dinosaurs: the role of niche partitioning in diversification. J Evol Biol 2019; 33:178-188. [PMID: 31622509 DOI: 10.1111/jeb.13557] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2019] [Revised: 09/28/2019] [Accepted: 10/04/2019] [Indexed: 11/30/2022]
Abstract
Oviraptorosaurs are bird-like theropod dinosaurs that thrived in the final pre-extinction ecosystems during the latest Cretaceous, and the beaked, toothless skulls of derived species are regarded as some of the most peculiar among dinosaurs. Their aberrant morphologies are hypothesized to have been caused by rapid evolution triggered by an ecological/biological driver, but little is known about how their skull shapes and functional abilities diversified. Here, we use quantitative techniques to study oviraptorosaur skull form and mandibular function. We demonstrate that the snout is particularly variable, that mandibular form and upper/lower beak form are significantly correlated with phylogeny, and that there is a strong and significant correlation between mandibular function and mandible/lower beak shape, suggesting a form-function association. The form-function relationship and phylogenetic signals, along with a moderate allometric signal in lower beak form, indicate that similar mechanisms governed beak shape in oviraptorosaurs and extant birds. The two derived oviraptorosaur clades, oviraptorids and caenagnathids, are significantly separated in morphospace and functional space, indicating that they partitioned niches. Oviraptorids coexisting in the same ecosystem are also widely spread in morphological and functional space, suggesting that they finely partitioned feeding niches, whereas caenagnathids exhibit extreme disparity in beak size. The diversity of skull form and function was likely key to the diversification and evolutionary success of oviraptorosaurs in the latest Cretaceous.
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Affiliation(s)
- Waisum Ma
- School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Stephen L Brusatte
- School of GeoSciences, University of Edinburgh, Edinburgh, United Kingdom
| | - Junchang Lü
- Institute of Geology, Chinese Academy of Geological Sciences, Beijing, China
| | - Manabu Sakamoto
- School of Biological Sciences, University of Reading, Reading, United Kingdom
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20
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Havstad JC, Smith NA. Fossils with Feathers and Philosophy of Science. Syst Biol 2019; 68:840-851. [PMID: 30753719 PMCID: PMC6701454 DOI: 10.1093/sysbio/syz010] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2018] [Revised: 02/05/2019] [Accepted: 02/06/2019] [Indexed: 01/14/2023] Open
Abstract
The last half century of paleornithological research has transformed the way that biologists perceive the evolutionary history of birds. This transformation has been driven, since 1969, by a series of exciting fossil discoveries combined with intense scientific debate over how best to interpret these discoveries. Ideally, as evidence accrues and results accumulate, interpretive scientific agreement forms. But this has not entirely happened in the debate over avian origins: the accumulation of scientific evidence and analyses has had some effect, but not a conclusive one, in terms of resolving the question of avian origins. Although the majority of biologists have come to accept that birds are dinosaurs, there is lingering and, in some quarters, strident opposition to this view. In order to both understand the ongoing disagreement about avian origins and generate a prediction about the future of the debate, here we use a revised model of scientific practice to assess the current and historical state of play surrounding the topic of bird evolutionary origins. Many scientists are familiar with the metascientific scholars Sir Karl Popper and Thomas Kuhn, and these are the primary figures that have been appealed to so far, in prior attempts to assess the dispute. But we demonstrate that a variation of Imre Lakatos's model of progressive versus degenerative research programmes provides a novel and productive assessment of the debate. We establish that a refurbished Lakatosian account both explains the intractability of the dispute and predicts a likely outcome for the debate about avian origins. In short, here, we offer a metascientific tool for rationally assessing competing theories-one that allows researchers involved in seemingly intractable scientific disputes to advance their debates.
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Affiliation(s)
- Joyce C Havstad
- Department of Philosophy, Oakland University, 146 Library Drive, Rochester, MI 48309, USA
| | - N Adam Smith
- Campbell Geology Museum, Clemson University, 140 Discovery Lane, Clemson SC 29634, USA
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21
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A new alvarezsaurian theropod from the Upper Jurassic Shishugou Formation of western China. Sci Rep 2019; 9:11727. [PMID: 31409823 PMCID: PMC6692367 DOI: 10.1038/s41598-019-48148-7] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2018] [Accepted: 07/17/2019] [Indexed: 11/18/2022] Open
Abstract
Alvarezsaurian dinosaurs, a group of bizarre theropods with greatly shortened and modified forelimbs, are known mostly from the Cretaceous of Asia and South America. Here we report a new alvarezsaurian, Shishugounykus inexpectus gen. et sp. nov, based on a specimen recovered from the Middle–Upper Jurassic Shishugou Formation of the Junggar Basin, western China. Together with two other alvarezsaurians from this formation, i.e., Haplocheirus sollers and Aorun zhaoi, these Shishugou forms represent the only known Jurassic alvarezsaurians worldwide. Similar to the two other Shishugou alvarezsaurians, this new alvarezsaurian displays early stages in the development of the highly modified alvarezsaurian forelimb, but it possesses a number of manual features closer to the typical coelurosaurian theropod condition. Combining morphological and histological features, our analysis indicates that the earliest known alvarezsaurians are variable in size and other important morphological features, and in particular display a mosaic distribution of forelimb features.
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22
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Stewart TA, Liang C, Cotney JL, Noonan JP, Sanger TJ, Wagner GP. Evidence against tetrapod-wide digit identities and for a limited frame shift in bird wings. Nat Commun 2019; 10:3244. [PMID: 31324809 PMCID: PMC6642197 DOI: 10.1038/s41467-019-11215-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2018] [Accepted: 06/28/2019] [Indexed: 02/03/2023] Open
Abstract
In crown group tetrapods, individual digits are homologized in relation to a pentadactyl ground plan. However, testing hypotheses of digit homology is challenging because it is unclear whether digits represent distinct and conserved gene regulatory states. Here we show dramatic evolutionary dynamism in the gene expression profiles of digits, challenging the notion that five digits have conserved developmental identities across amniotes. Transcriptomics shows diversity in the patterns of gene expression differentiation of digits, although the anterior-most digit of the pentadactyl limb has a unique, conserved expression profile. Further, we identify a core set of transcription factors that are differentially expressed among the digits of amniote limbs; their spatial expression domains, however, vary between species. In light of these results, we reevaluate the frame shift hypothesis of avian wing evolution and conclude only the identity of the anterior-most digit has shifted position, suggesting a 1,3,4 digit identity in the bird wing.
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Affiliation(s)
- Thomas A Stewart
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA. .,Minnesota Center for Philosophy of Science, University of Minnesota, Minneapolis, MN, 55455, USA. .,Department of Organismal Biology and Anatomy, The University of Chicago, Chicago, IL, 60637, USA.
| | - Cong Liang
- Systems Biology Institute, Yale University, West Haven, CT, 06516, USA.,Center for Applied Mathematics, Tianjin University, Tianjin, 300072, China
| | - Justin L Cotney
- Department of Genetics and Genome Sciences, UConn Health, Farmington, CT, 06030, USA
| | - James P Noonan
- Department of Genetics, Yale School of Medicine, New Haven, CT, 06520, USA
| | - Thomas J Sanger
- Department of Biology, Loyola University in Chicago, Chicago, IL, 60660, USA
| | - Günter P Wagner
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06520, USA. .,Systems Biology Institute, Yale University, West Haven, CT, 06516, USA.
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23
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Langer MC, Martins NDO, Manzig PC, Ferreira GDS, Marsola JCDA, Fortes E, Lima R, Sant'ana LCF, Vidal LDS, Lorençato RHDS, Ezcurra MD. A new desert-dwelling dinosaur (Theropoda, Noasaurinae) from the Cretaceous of south Brazil. Sci Rep 2019; 9:9379. [PMID: 31243312 PMCID: PMC6594977 DOI: 10.1038/s41598-019-45306-9] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2019] [Accepted: 06/04/2019] [Indexed: 11/09/2022] Open
Abstract
Noasaurines form an enigmatic group of small-bodied predatory theropod dinosaurs known from the Late Cretaceous of Gondwana. They are relatively rare, with notable records in Argentina and Madagascar, and possible remains reported for Brazil, India, and continental Africa. In south-central Brazil, the deposits of the Bauru Basin have yielded a rich tetrapod fauna, which is concentrated in the Bauru Group. The mainly aeolian deposits of the Caiuá Group, on the contrary, bear a scarce fossil record composed only of lizards, turtles, and pterosaurs. Here, we describe the first dinosaur of the Caiuá Group, which also represents the best-preserved theropod of the entire Bauru Basin known to date. The recovered skeletal parts (vertebrae, girdles, limbs, and scarce cranial elements) show that the new taxon was just over 1 m long, with a unique anatomy among theropods. The shafts of its metatarsals II and IV are very lateromedially compressed, as are the blade-like ungual phalanges of the respective digits. This implies that the new taxon could have been functionally monodactyl, with a main central weight-bearing digit, flanked by neighbouring elements positioned very close to digit III or even held free of the ground. Such anatomical adaptation is formerly unrecorded among archosaurs, but has been previously inferred from footprints of the same stratigraphic unit that yielded the new dinosaur. A phylogenetic analysis nests the new taxon within the Noasaurinae clade, which is unresolved because of the multiple alternative positions that Noasaurus leali can acquire in the optimal trees. The exclusion of the latter form results in positioning the new dinosaur as the sister-taxon of the Argentinean Velocisaurus unicus.
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Affiliation(s)
- Max Cardoso Langer
- Laboratório de Paleontologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto/SP, Brazil.
| | - Neurides de Oliveira Martins
- Museu de Paleontologia de Cruzeiro do Oeste, Rua João Ormino de Rezende, 686, 87400-000, Cruzeiro do Oeste/PR, Brazil
- Centro de Estudos Paleontologicos, Ambientais e Culturais (Cepac), Rua Edmundo Mercer Junior, 1308, 87400-000, Cruzeiro do Oeste/PR, Brazil
| | - Paulo César Manzig
- Museu de Paleontologia de Cruzeiro do Oeste, Rua João Ormino de Rezende, 686, 87400-000, Cruzeiro do Oeste/PR, Brazil
| | - Gabriel de Souza Ferreira
- Laboratório de Paleontologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto/SP, Brazil
| | - Júlio César de Almeida Marsola
- Laboratório de Paleontologia, Faculdade de Filosofia, Ciências e Letras de Ribeirão Preto, Universidade de São Paulo, Av. Bandeirantes, 3900, 14040-901, Ribeirão Preto/SP, Brazil
| | - Edison Fortes
- Programa de Pós-Graduação em Geografia (PGE), Universidade Estadual de Maringá, Avenida Colombo, 5790, 87020-900, Maringá/PR, Brazil
| | - Rosana Lima
- Programa de Pós-Graduação em Geografia (PGE), Universidade Estadual de Maringá, Avenida Colombo, 5790, 87020-900, Maringá/PR, Brazil
- Grupo de Estudos Multidisciplinares do Ambiente (GEMA), Universidade Estadual de Maringá, Avenida Colombo, 5790, 87020-900, Maringá/PR, Brazil
| | - Lucas Cesar Frediani Sant'ana
- Programa de Pós-Graduação em Geografia (PGE), Universidade Estadual de Maringá, Avenida Colombo, 5790, 87020-900, Maringá/PR, Brazil
| | - Luciano da Silva Vidal
- Laboratório de Macrofósseis, Universidade Federal do Rio de Janeiro, Av. Athos da Silveira Ramos, 274, 21941-611, Rio de Janeiro/RJ, Brazil
| | | | - Martín Daniel Ezcurra
- Sección Paleontología de Vertebrados, CONICET-Museo Argentino de Ciencias Naturales "Bernardino Rivadavia", Avenida Ángel Gallardo, 470, C1405DJR, Buenos Aires, Argentina
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24
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Kawahata K, Cordeiro IR, Ueda S, Sheng G, Moriyama Y, Nishimori C, Yu R, Koizumi M, Okabe M, Tanaka M. Evolution of the avian digital pattern. Sci Rep 2019; 9:8560. [PMID: 31189916 PMCID: PMC6561939 DOI: 10.1038/s41598-019-44913-w] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2019] [Accepted: 05/23/2019] [Indexed: 11/26/2022] Open
Abstract
Variation in digit number has occurred multiple times in the history of archosaur evolution. The five digits of dinosaur limbs were reduced to three in bird forelimbs, and were further reduced in the vestigial forelimbs of the emu. Regulation of digit number has been investigated previously by examining genes involved in anterior-posterior patterning in forelimb buds among emu (Dromaius novaehollandiae), chicken (Gallus gallus) and zebra finch (Taeniopygia guttata). It was described that the expression of posterior genes are conserved among these three birds, whereas expression of anterior genes Gli3 and Alx4 varied significantly. Here we re-examined the expression pattern of Gli3 and Alx4 in the forelimb of emu, chicken and zebra finch. We found that Gli3 is expressed in the anterior region, although its range varied among species, and that the expression pattern of Alx4 in forelimb buds is broadly conserved in a stage-specific manner. We also found that the dynamic expression pattern of the BMP antagonist Gremlin1 (Grem1) in limb buds, which is critical for autopodial expansion, was consistent with the digital pattern of emu, chicken and zebra finch. Furthermore, in emu, variation among individuals was observed in the width of Grem1 expression in forelimb buds, as well as in the adult skeletal pattern. Our results support the view that the signalling system that regulates the dynamic expression of Grem1 in the limb bud contributes substantially to variations in avian digital patterns.
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Affiliation(s)
- Kenta Kawahata
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | | | - Shogo Ueda
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Laboratory for Immunotherapy, RIKEN Center for Integrative Medical Sciences, Yokohama, Japan
| | - Guojun Sheng
- International Research Center for Medical Sciences, Kumamoto University, Kumamoto, Japan.,RIKEN Center for Developmental Biology, Kobe, Japan
| | - Yuuta Moriyama
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.,Department of Physics and Mathematics, College of Science and Engineering, Aoyama Gakuin University, Sagamihara, Japan
| | - Chika Nishimori
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Reiko Yu
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan
| | - Makoto Koizumi
- Laboratory Animal Facilities, The Jikei University School of Medicine, Tokyo, Japan
| | - Masataka Okabe
- Department of Anatomy, The Jikei University School of Medicine, Tokyo, Japan
| | - Mikiko Tanaka
- School of Life Science and Technology, Tokyo Institute of Technology, Yokohama, Japan.
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25
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Rauhut OWM, Tischlinger H, Foth C. A non-archaeopterygid avialan theropod from the Late Jurassic of southern Germany. eLife 2019; 8:e43789. [PMID: 31084702 PMCID: PMC6516837 DOI: 10.7554/elife.43789] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2018] [Accepted: 04/10/2019] [Indexed: 01/05/2023] Open
Abstract
The Late Jurassic 'Solnhofen Limestones' are famous for their exceptionally preserved fossils, including the urvogel Archaeopteryx, which has played a pivotal role in the discussion of bird origins. Here we describe a new, non-archaeopterygid avialan from the Lower Tithonian Mörnsheim Formation of the Solnhofen Archipelago, Alcmonavis poeschli gen. et sp. nov. Represented by a right wing, Alcmonavis shows several derived characters, including a pronounced attachment for the pectoralis muscle, a pronounced tuberculum bicipitale radii, and a robust second manual digit, indicating that it is a more derived avialan than Archaeopteryx. Several modifications, especially in muscle attachments of muscles that in modern birds are related to the downstroke of the wing, indicate an increased adaptation of the forelimb for active flapping flight in the early evolution of birds. This discovery indicates higher avialan diversity in the Late Jurassic than previously recognized.
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Affiliation(s)
- Oliver WM Rauhut
- Staatliche naturwissenschaftliche Sammlungen Bayerns (SNSB)Bayerische Staatssammlung für Paläontologie und GeologieMünchenGermany
- Department for Earth and Environmental Sciences, Palaeontology and GeobiologyLudwig-Maximilians-UniversitätMünchenGermany
- GeoBioCenterLudwig-Maximilians-UniversitätMünchenGermany
| | | | - Christian Foth
- Department of GeosciencesUniversité de FribourgFribourgSwitzerland
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26
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An abelisaurid (Dinosauria: Theropoda) ilium from the Upper Cretaceous (Cenomanian) of the Kem Kem beds, Morocco. PLoS One 2019; 14:e0214055. [PMID: 30939139 PMCID: PMC6445567 DOI: 10.1371/journal.pone.0214055] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2018] [Accepted: 03/06/2019] [Indexed: 11/19/2022] Open
Abstract
Abelisaurid theropods first appear in the fossil record in the early Jurassic and survived at least until the end of the Mesozoic. They were known to have dominated South America, India and Madagascar but were not so abundant in North America or Asia. Much less is known about their presence in Africa, although there has been several recent discoveries of abelisaurid material in Morocco. Here we add a partially preserved ilium to a growing body of evidence that suggests abelisaurs might also have dominated Africa.
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27
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A new transitional therizinosaurian theropod from the Early Cretaceous Jehol Biota of China. Sci Rep 2019; 9:5026. [PMID: 30903000 PMCID: PMC6430829 DOI: 10.1038/s41598-019-41560-z] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2018] [Accepted: 03/06/2019] [Indexed: 11/30/2022] Open
Abstract
Therizinosaurian theropods evolved many highly specialized osteological features in association with their bulky proportions, which were unusual in the context of the generally gracile Theropoda. Here we report a new therizinosaur, Lingyuanosaurus sihedangensis gen. et sp. nov., based on a specimen recovered from the Lower Cretaceous Jehol Group of Lingyuan, Liaoning Province, China, which displays a combination of plesiomorphic and derived features. Most notably, the specimen is characterized by posterior dorsal vertebrae with a complex and unusual laminar structure; an ilium with a highly dorsoventrally expanded preacetabular process showing only slight lateral flaring of the ventral margin, a strongly anterodorsally inclined iliac blade, a small postacetabular process with a strongly concave dorsal margin, and a relatively robust pubic peduncle with a posteroventrally facing distal articular surface; a straight and robust femur with a small lesser trochanter; and a tibia that is longer than the femur. Phylogenetic analysis places Lingyuanosaurus in an intermediate position within Therizinosauria, i.e., between the early-branching therizinosaurs such as Falcarius, Jianchangosaurus, and Beipiaosaurus and the late-branching ones such as Alxasaurus and Therizinosaurus. This new therizinosaur sheds additional light on the evolution of major therizinosaurian characteristics, including particularly the distinctive pelvic girdle and hindlimb morphology seen in this group.
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28
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Mannion PD, Upchurch P, Schwarz D, Wings O. Taxonomic affinities of the putative titanosaurs from the Late Jurassic Tendaguru Formation of Tanzania: phylogenetic and biogeographic implications for eusauropod dinosaur evolution. Zool J Linn Soc 2019. [DOI: 10.1093/zoolinnean/zly068] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
Affiliation(s)
- Philip D Mannion
- Department of Earth Science and Engineering, Imperial College London, London, UK
| | - Paul Upchurch
- Department of Earth Sciences, University College London, London, UK
| | | | - Oliver Wings
- Niedersächsisches Landesmuseum Hannover, Hannover, Germany
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29
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Dal Sasso C, Maganuco S, Cau A. The oldest ceratosaurian (Dinosauria: Theropoda), from the Lower Jurassic of Italy, sheds light on the evolution of the three-fingered hand of birds. PeerJ 2018; 6:e5976. [PMID: 30588396 PMCID: PMC6304160 DOI: 10.7717/peerj.5976] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2018] [Accepted: 10/22/2018] [Indexed: 12/18/2022] Open
Abstract
The homology of the tridactyl hand of birds is a still debated subject, with both paleontological and developmental evidence used in support of alternative identity patterns in the avian fingers. With its simplified phalangeal morphology, the Late Jurassic ceratosaurian Limusaurus has been argued to support a II-III-IV digital identity in birds and a complex pattern of homeotic transformations in three-fingered (tetanuran) theropods. We report a new large-bodied theropod, Saltriovenator zanellai gen. et sp. nov., based on a partial skeleton from the marine Saltrio Formation (Sinemurian, lowermost Jurassic) of Lombardy (Northern Italy). Taphonomical analyses show bone bioerosion by marine invertebrates (first record for dinosaurian remains) and suggest a complex history for the carcass before being deposited on a well-oxygenated and well-illuminated sea bottom. Saltriovenator shows a mosaic of features seen in four-fingered theropods and in basal tetanurans. Phylogenetic analysis supports sister taxon relationships between the new Italian theropod and the younger Early Jurassic Berberosaurus from Morocco, in a lineage which is the basalmost of Ceratosauria. Compared to the atrophied hand of later members of Ceratosauria, Saltriovenator demonstrates that a fully functional hand, well-adapted for struggling and grasping, was primitively present in ceratosaurians. Ancestral state reconstruction along the avian stem supports 2-3-4-1-X and 2-3-4-0-X as the manual phalangeal formulae at the roots of Ceratosauria and Tetanurae, confirming the I-II-III pattern in the homology of the avian fingers. Accordingly, the peculiar hand of Limusaurus represents a derived condition restricted to late-diverging ceratosaurians and cannot help in elucidating the origin of the three-fingered condition of tetanurans. The evolution of the tridactyl hand of birds is explained by step-wise lateral simplification among non-tetanuran theropod dinosaurs, followed by a single primary axis shift from digit position 4 to 3 at the root of Tetanurae once the fourth finger was completely lost, which allowed independent losses of the vestigial fourth metacarpal among allosaurians, tyrannosauroids, and maniraptoromorphs. With an estimated body length of 7.5 m, Saltriovenator is the largest and most robust theropod from the Early Jurassic, pre-dating the occurrence in theropods of a body mass approaching 1,000 Kg by over 25 My. The radiation of larger and relatively stockier averostran theropods earlier than previously known may represent one of the factors that ignited the trend toward gigantism in Early Jurassic sauropods.
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Affiliation(s)
| | | | - Andrea Cau
- Museo Geologico "Giovanni Capellini", Bologna, Italy
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30
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Zheng X, Wang X, Sullivan C, Zhang X, Zhang F, Wang Y, Li F, Xu X. Exceptional dinosaur fossils reveal early origin of avian-style digestion. Sci Rep 2018; 8:14217. [PMID: 30242170 PMCID: PMC6155034 DOI: 10.1038/s41598-018-32202-x] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/21/2017] [Accepted: 05/15/2018] [Indexed: 11/17/2022] Open
Abstract
Birds have a highly specialized and efficient digestive system, but when this system originated remains uncertain. Here we report six gastric pellets attributable to the recently discovered 160-million-year-old troodontid dinosaur Anchiornis, which is among the key taxa for understanding the transition to birds. The gastric pellets contain lightly acid-etched lizard bones or fish scales, and some are associated with Anchiornis skeletons or even situated within the oesophagus. Anchiornis is the earliest and most basal theropod known to have produced gastric pellets. In combination with other lines of evidence, the pellets suggest that a digestive system resembling that of modern birds was already present in basal members of the Paraves, a clade including troodontids, dromaeosaurids, and birds, and that the evolution of modern avian digestion may have been related to the appearance of aerial locomotion in this lineage.
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Affiliation(s)
- Xiaoting Zheng
- Institute of Geology and Paleontology, Linyi University, Linyi City, Shandong, 276005, China.,Shandong Tianyu Museum of Nature, Pingyi, Shandong, 273300, China
| | - Xiaoli Wang
- Institute of Geology and Paleontology, Linyi University, Linyi City, Shandong, 276005, China.
| | - Corwin Sullivan
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, T6G 2E9, Canada.,Philip J. Currie Dinosaur Museum, Wembley, Alberta, T0H 3S0, Canada
| | - Xiaomei Zhang
- Shandong Tianyu Museum of Nature, Pingyi, Shandong, 273300, China
| | - Fucheng Zhang
- Institute of Geology and Paleontology, Linyi University, Linyi City, Shandong, 276005, China
| | - Yan Wang
- Institute of Geology and Paleontology, Linyi University, Linyi City, Shandong, 276005, China
| | - Feng Li
- University of Chinese Academy of Sciences, Beijing, 100049, People's Republic of China.,Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, 100044, China.
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31
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Xu X, Choiniere J, Tan Q, Benson RBJ, Clark J, Sullivan C, Zhao Q, Han F, Ma Q, He Y, Wang S, Xing H, Tan L. Two Early Cretaceous Fossils Document Transitional Stages in Alvarezsaurian Dinosaur Evolution. Curr Biol 2018; 28:2853-2860.e3. [PMID: 30146153 DOI: 10.1016/j.cub.2018.07.057] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2018] [Revised: 06/04/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
Abstract
Highly specialized animals are often difficult to place phylogenetically. The Late Cretaceous members of Alvarezsauria represent such an example, having been posited as members of various theropod lineages, including birds [1-11]. A 70-million-year ghost lineage exists between them and the Late Jurassic putative alvarezsaurian Haplocheirus [12], which preserves so few derived features that its membership in Alvarezsauria has recently been questioned [13]. If Haplocheirus is indeed an alvarezsaurian, then the 70-million-year gap between Haplocheirus and other alvarezsaurians represents the longest temporal hiatus within the fossil record of any theropod subgroup [14]. Here we report two new alvarezsaurians from the Early Cretaceous of Western China that document successive, transitional stages in alvarezsaurian evolution. They provide further support for Haplocheirus as an alvarezsaurian and for alvarezsaurians as basal maniraptorans. Furthermore, they suggest that the early biogeographic history of the Alvarezsauria involved dispersals from Asia to other continents. The new specimens are temporally, morphologically, and functionally intermediate between Haplocheirus and other known alvarezsaurians and provide a striking example of the evolutionary transition from a typical theropod forelimb configuration (i.e., the relatively long arm and three-digit grasping hand of typical tetanuran form in early-branching alvarezsaurians) to a highly specialized one (i.e., the highly modified and shortened arm and one-digit digging hand of Late Cretaceous parvicursorines such as Linhenykus [1, 15]). Comprehensive analyses incorporating data from these new finds show that the specialized alvarezsaurian forelimb morphology evolved slowly and in a mosaic fashion during the Cretaceous.
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Affiliation(s)
- Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xiwai Street, Beijing 100044, China; CAS Center for Excellence in Life and Paleoenvironment, 142 Xiwai Street, Beijing 100044, China; Centre for Research and Education on Biological Evolution and Environment, 163 Xianlin Road, Nanjing University, Nanjing 210045, China.
| | - Jonah Choiniere
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa; Department of Vertebrate Paleontology and Richard Gilder Graduate School, American Museum of Natural History, Central Park West at 79(th) Street, New York, NY 10024, USA
| | - Qingwei Tan
- Long Hao Institute of Geology and Paleontology, Jia 29, Fengzhou Road, Hohhot, Nei Mongol 010010, China
| | - Roger B J Benson
- Evolutionary Studies Institute, University of the Witwatersrand, Private Bag 3, Johannesburg WITS 2050, South Africa; Department of Earth Sciences, University of Oxford, South Parks Road, Oxford OX1 3AN, UK
| | - James Clark
- Department of Biological Sciences, George Washington University, 2023 G Street NW, Washington, DC 20052, USA; Centre for Vertebrate Evolutionary Biology, Yunnan University, 2 Green Lake North Road, Kunming 650091, China
| | - Corwin Sullivan
- Department of Biological Sciences, University of Alberta, 11455 Saskatchewan Drive, Edmonton, AB T6G 2E9, Canada; Philip J. Currie Dinosaur Museum, 9301 112 Avenue, Wembley, AB T0H 3S0, Canada
| | - Qi Zhao
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xiwai Street, Beijing 100044, China
| | - Fenglu Han
- School of Earth Sciences, China University of Geosciences, 388 Lumo Road, Wuhan 430074, China
| | - Qingyu Ma
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xiwai Street, Beijing 100044, China
| | - Yiming He
- School of Earth Sciences and Engineering, Nanjing University, 163 Xianlin Road, Nanjing 210045, China
| | - Shuo Wang
- College of Life Science, Capital Normal Univerity, 105 West 3(rd) Ring Road North, Beijing 100048, China
| | - Hai Xing
- Beijing Museum of Natural History, Beijing Academy of Science and Technology, 126 South Tianqiao Street, Beijing 100050, China
| | - Lin Tan
- Long Hao Institute of Geology and Paleontology, Jia 29, Fengzhou Road, Hohhot, Nei Mongol 010010, China
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32
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Ceratosaur palaeobiology: new insights on evolution and ecology of the southern rulers. Sci Rep 2018; 8:9730. [PMID: 29950661 PMCID: PMC6021374 DOI: 10.1038/s41598-018-28154-x] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/03/2017] [Accepted: 06/12/2018] [Indexed: 11/28/2022] Open
Abstract
Ceratosaur theropods ruled the Southern Hemisphere until the end of the Late Cretaceous. However, their origin was earlier, during the Early Jurassic, a fact which allowed the group to reach great morphological diversity. The body plans of the two main branches (Noasauridae and new name Etrigansauria: Ceratosauridae + Abelisauridae) are quite different; nevertheless, they are sister taxa. Abelisaurids have lost the ability to grasp in the most derived taxa, but the reduced forelimb might have had some display function. The ontogenetic changes are well known in Limusaurus which lost all their teeth and probably changed the dietary preference at maturity. The results presented here suggest that abelisaurids had different soft tissues on the skull. These tissues might have been associated with evolution of a strong cervicocephalic complex and should have allowed derived taxa (e.g. Majungasaurus and Carnotaurus) to have low-displacement headbutting matches. The ability to live in different semi-arid environment plus high morphological disparity allowed the ceratosaurs to become an evolutionary success.
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33
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Rauhut OWM, Foth C, Tischlinger H. The oldest Archaeopteryx (Theropoda: Avialiae): a new specimen from the Kimmeridgian/Tithonian boundary of Schamhaupten, Bavaria. PeerJ 2018; 6:e4191. [PMID: 29383285 PMCID: PMC5788062 DOI: 10.7717/peerj.4191] [Citation(s) in RCA: 55] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2017] [Accepted: 12/04/2017] [Indexed: 11/25/2022] Open
Abstract
The iconic primeval bird Archaeopteryx was so far mainly known from the Altmühltal Formation (early Tithonian) of Bavaria, southern Germany, with one specimen having been found in the overlying Mörnsheim Formation. A new specimen (the 12th skeletal specimen) from the earliest Tithonian Painten Formation of Schamhaupten (Bavaria) represents the so far oldest representative of the genus. The new specimen shows several interesting anatomical details, including the presence of a postorbital in contact with the jugal, the presence of a separate prefrontal and coronoid, and opisthocoelous mid-cervical vertebrae. Based on observations on the new specimen, we discuss several problematic issues concerning Archaeopteryx, including the monophyly and diagnosis of the genus, the absence/presence of the sternum, the position of the gastralia, and variation in morphometrics and dental morphology in that genus. Based on a new diagnosis for the genus Archaeopteryx, the Berlin, Eichstätt, Solnhofen, Munich, Daiting, Thermopolis, 11th, and 12th specimens can be referred to this genus with high certainty. The Maxberg specimen is very probably also an Archaeopteryx, based on overall similarity, although none of the diagnostic characters can be evaluated with certainty. The ninth specimen (‘chicken wing’) might be Archaeopteryx, but cannot be referred to the genus with any certainty. In comparison with other paravians, the presence of distally thickened anterior pectoral ribs indicates that a rather large cartilagenous sternum was present in this taxon. In contrast to non-opisthopubic theropods, opisthopubic taxa, such as Archaeopteryx and many other paravians, have the posterior end of the gastral basket preserved at about half-length of the pubis, which might reflect the post-mortem collapse of enlarged abdominal air sacs in these taxa. Specimens that can be referred to Archaeopteryx show a high amount of variation, both in the morphometrics of the limb bones as well as in the dentition. In respect to the latter aspect, variation is found in tooth number, spacing, orientation, and morphology, with no two specimens showing the exact same pattern. The significance of this variation is unclear, and possible explanations reach from high intraspecific (and possibly ontogenetic and/or sexual dimorphic) variation to the possibility that the known specimens represent a ‘species flock’ of Archaeopteryx, possibly due to island speciation after the initial dispersal of the genus into the Solnhofen Archipelago.
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Affiliation(s)
- Oliver W M Rauhut
- SNSB-Bayerische Staatssammlung für Paläontologie und Geologie, Munich, Germany.,Department of Earth and Environmental Sciences, Ludwig-Maximilians University, Munich, Germany.,GeoBioCenter, Ludwig-Maximilians University, Munich, Germany
| | - Christian Foth
- Department of Geosciences, Université de Fribourg, Fribourg, Switzerland.,Staatliches Museum für Naturkunde, Stuttgart, Germany
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A bony-crested Jurassic dinosaur with evidence of iridescent plumage highlights complexity in early paravian evolution. Nat Commun 2018; 9:217. [PMID: 29335537 PMCID: PMC5768872 DOI: 10.1038/s41467-017-02515-y] [Citation(s) in RCA: 47] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/17/2017] [Accepted: 12/05/2017] [Indexed: 12/25/2022] Open
Abstract
The Jurassic Yanliao theropods have offered rare glimpses of the early paravian evolution and particularly of bird origins, but, with the exception of the bizarre scansoriopterygids, they have shown similar skeletal and integumentary morphologies. Here we report a distinctive new Yanliao theropod species bearing prominent lacrimal crests, bony ornaments previously known from more basal theropods. It shows longer arm and leg feathers than Anchiornis and tail feathers with asymmetrical vanes forming a tail surface area even larger than that in Archaeopteryx. Nanostructures, interpreted as melanosomes, are morphologically similar to organized, platelet-shaped organelles that produce bright iridescent colours in extant birds. The new species indicates the presence of bony ornaments, feather colour and flight-related features consistent with proposed rapid character evolution and significant diversity in signalling and locomotor strategies near bird origins. A number of paravian dinosaurs have been described from the Jurassic Yanliao biota, but these have tended to be morphologically similar to Archaeopteryx. Here, Hu. describe the new paravian dinosaur, Caihong juji gen. et sp. nov., which possesses a suite of unusual skeletal and feather characteristics.
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Barta DE, Nesbitt SJ, Norell MA. The evolution of the manus of early theropod dinosaurs is characterized by high inter- and intraspecific variation. J Anat 2018; 232:80-104. [PMID: 29114853 PMCID: PMC5735062 DOI: 10.1111/joa.12719] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2017] [Indexed: 11/27/2022] Open
Abstract
The origin of the avian hand, with its reduced and fused carpals and digits, from the five-fingered hands and complex wrists of early dinosaurs represents one of the major transformations of manus morphology among tetrapods. Much attention has been directed to the later part of this transition, from four- to three-fingered taxa. However, earlier anatomical changes may have influenced these later modifications, possibly paving the way for a later frameshift in digit identities. We investigate the five- to four-fingered transition among early dinosaurs, along with changes in carpus morphology. New three-dimensional reconstructions from computed tomography data of the manus of the Triassic and Early Jurassic theropod dinosaurs Coelophysis bauri and Megapnosaurus rhodesiensis are described and compared intra- and interspecifically. Several novel findings emerge from these reconstructions and comparisons, including the first evidence of an ossified centrale and a free intermedium in some C. bauri specimens, as well as confirmation of the presence of a vestigial fifth metacarpal in this taxon. Additionally, a specimen of C. bauri and an unnamed coelophysoid from the Upper Triassic Hayden Quarry, New Mexico, are to our knowledge the only theropods (other than alvarezsaurs and birds) in which all of the distal carpals are completely fused together into a single unit. Several differences between the manus of C. bauri and M. rhodesiensis are also identified. We review the evolution of the archosauromorph manus more broadly in light of these new data, and caution against incorporating carpal characters in phylogenetic analyses of fine-scale relationships of Archosauromorpha, in light of the high degree of observed polymorphism in taxa for which large sample sizes are available, such as the theropod Coelophysis and the sauropodomorph Plateosaurus. We also find that the reduction of the carpus and ultimate loss of the fourth and fifth digits among early dinosaurs did not proceed in a neat, stepwise fashion, but was characterized by multiple losses and possible gains of carpals, metacarpals and phalanges. Taken together, the high degree of intra- and interspecific variability in the number and identities of carpals, and the state of reduction of the fourth and fifth digits suggest the presence of a 'zone of developmental variability' in early dinosaur manus evolution, from which novel avian-like morphologies eventually emerged and became channelized among later theropod clades.
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Affiliation(s)
- Daniel E. Barta
- Richard Gilder Graduate SchoolAmerican Museum of Natural HistoryNew YorkNYUSA
- Division of PaleontologyAmerican Museum of Natural HistoryNew YorkNYUSA
| | - Sterling J. Nesbitt
- Division of PaleontologyAmerican Museum of Natural HistoryNew YorkNYUSA
- Department of GeosciencesVirginia Polytechnic Institute and State UniversityBlacksburgVAUSA
| | - Mark A. Norell
- Richard Gilder Graduate SchoolAmerican Museum of Natural HistoryNew YorkNYUSA
- Division of PaleontologyAmerican Museum of Natural HistoryNew YorkNYUSA
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Towers M. Evolution of antero-posterior patterning of the limb: Insights from the chick. Genesis 2018; 56:e23047. [PMID: 28734068 PMCID: PMC5811799 DOI: 10.1002/dvg.23047] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2017] [Revised: 06/23/2017] [Accepted: 06/27/2017] [Indexed: 01/30/2023]
Abstract
The developing limbs of chicken embryos have served as pioneering models for understanding pattern formation for over a century. The ease with which chick wing and leg buds can be experimentally manipulated, while the embryo is still in the egg, has resulted in the discovery of important developmental organisers, and subsequently, the signals that they produce. Sonic hedgehog (Shh) is produced by mesenchyme cells of the polarizing region at the posterior margin of the limb bud and specifies positional values across the antero-posterior axis (the axis running from the thumb to the little finger). Detailed experimental embryology has revealed the fundamental parameters required to specify antero-posterior positional values in response to Shh signaling in chick wing and leg buds. In this review, the evolution of the avian wing and leg will be discussed in the broad context of tetrapod paleontology, and more specifically, ancestral theropod dinosaur paleontology. How the parameters that dictate antero-posterior patterning could have been modulated to produce the avian wing and leg digit patterns will be considered. Finally, broader speculations will be made regarding what the antero-posterior patterning of chick limbs can tell us about the evolution of other digit patterns, including those that were found in the limbs of the earliest tetrapods.
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Affiliation(s)
- Matthew Towers
- Department of Biomedical ScienceThe Bateson Centre, University of SheffieldWestern BankSheffieldS10 2TNUnited Kingdom
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Averianov A, Sues HD. The oldest record of Alvarezsauridae (Dinosauria: Theropoda) in the Northern Hemisphere. PLoS One 2017; 12:e0186254. [PMID: 29069094 PMCID: PMC5656310 DOI: 10.1371/journal.pone.0186254] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2017] [Accepted: 09/27/2017] [Indexed: 11/24/2022] Open
Abstract
Procoelous caudal vertebrae, a carpometacarpus with a hypertrophied metacarpal II, and robust proximal and ungual phalanges of manual digit II of a small theropod dinosaur from the Upper Cretaceous (Turonian) Bissekty Formation at Dzharakuduk, Uzbekistan, show unequivocal synapomorphies of the clade Alvarezsauridae and thus are referred to it. The caudal vertebrae have a unique longitudinal canal within the neural arch. The carpometacarpus, with metacarpal III occupying about one third of the width of the carpometacarpus, shows the most plesiomorphic stage of the evolution of the forelimb among known alvarezsaurids. The proximal phalanx of manual digit II differs from the corresponding bone in Parvicursorinae in having a less asymmetrical proximal articular surface without a dorsal process and short ventral ridges. The ungual phalanx of manual digit II has laterally open ventral foramina. The Bissekty alvarezsaurid possibly represents a basal parvicursorine and is the stratigraphically oldest known alvarezsaurid in Asia known to date.
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Affiliation(s)
- Alexander Averianov
- Zoological Institute of the Russian Academy of Sciences, Universitetskaya nab. 1, Saint Petersburg, Russia
- Institute of Geology and Petroleum Technology, Kazan Federal University, Kazan, Russia
| | - Hans-Dieter Sues
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, Washington DC, United States of America
- * E-mail:
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Burch SH. Myology of the forelimb of Majungasaurus crenatissimus (Theropoda, Abelisauridae) and the morphological consequences of extreme limb reduction. J Anat 2017; 231:515-531. [PMID: 28762500 DOI: 10.1111/joa.12660] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 05/25/2017] [Indexed: 12/12/2022] Open
Abstract
Forelimb reduction occurred independently in multiple lineages of theropod dinosaurs. Although tyrannosaurs are renowned for their tiny, two-fingered forelimbs, the degree of their reduction in length is surpassed by abelisaurids, which possess an unusual morphology distinct from that of other theropods. The forelimbs of abelisaurids are short but robust and exhibit numerous crests, tubercles, and scars that allow for inferences of muscle attachment sites. Phylogenetically based reconstructions of the musculature were used in combination with close examination of the osteology in the Malagasy abelisaurid Majungasaurus to create detailed muscle maps of the forelimbs, and patterns of the muscular and bony morphology were compared with those of extant tetrapods with reduced or vestigial limbs. The lever arms of muscles crossing the glenohumeral joint are shortened relative to the basal condition, reducing the torque of these muscles but increasing the excursion of the humerus. Fusion of the antebrachial muscles into a set of flexors and extensors is common in other tetrapods and occurred to some extent in Majungasaurus. However, the presence of tubercles on the antebrachial and manual elements of abelisaurids indicates that many of the individual distal muscles acting on the wrist and digits were retained. Majungasaurus shows some signs of the advanced stages of forelimb reduction preceding limb loss, while also exhibiting features suggesting that the forelimb was not completely functionless. The conformation of abelisaurid forelimb musculature was unique among theropods and further emphasizes the unusual morphology of the forelimbs in this clade.
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Affiliation(s)
- Sara H Burch
- Department of Biology, SUNY Geneseo, Geneseo, New York, USA
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Mosaic evolution in an asymmetrically feathered troodontid dinosaur with transitional features. Nat Commun 2017; 8:14972. [PMID: 28463233 PMCID: PMC5418581 DOI: 10.1038/ncomms14972] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2016] [Accepted: 02/16/2017] [Indexed: 11/08/2022] Open
Abstract
Asymmetrical feathers have been associated with flight capability but are also found in species that do not fly, and their appearance was a major event in feather evolution. Among non-avialan theropods, they are only known in microraptorine dromaeosaurids. Here we report a new troodontid, Jianianhualong tengi gen. et sp. nov., from the Lower Cretaceous Jehol Group of China, that has anatomical features that are transitional between long-armed basal troodontids and derived short-armed ones, shedding new light on troodontid character evolution. It indicates that troodontid feathering is similar to Archaeopteryx in having large arm and leg feathers as well as frond-like tail feathering, confirming that these feathering characteristics were widely present among basal paravians. Most significantly, the taxon has the earliest known asymmetrical troodontid feathers, suggesting that feather asymmetry was ancestral to Paraves. This taxon also displays a mosaic distribution of characters like Sinusonasus, another troodontid with transitional anatomical features. Troodontids were theropod dinosaurs closely related to birds. Here, Xu and colleagues describe a new, feathered troodontid species, Jianianhualong tengi, dating from the Lower Cretaceous period in China that provides insight into troodontid mosaic evolution and paravian feathering.
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40
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Saxena A, Towers M, Cooper KL. The origins, scaling and loss of tetrapod digits. Philos Trans R Soc Lond B Biol Sci 2017; 372:rstb.2015.0482. [PMID: 27994123 PMCID: PMC5182414 DOI: 10.1098/rstb.2015.0482] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/05/2016] [Indexed: 12/19/2022] Open
Abstract
Many of the great morphologists of the nineteenth century marvelled at similarities between the limbs of diverse species, and Charles Darwin noted these homologies as significant supporting evidence for descent with modification from a common ancestor. Sir Richard Owen also took great care to highlight each of the elements of the forelimb and hindlimb in a multitude of species with focused attention on the homology between the hoof of the horse and the middle digit of man. The ensuing decades brought about a convergence of palaeontology, experimental embryology and molecular biology to lend further support to the homologies of tetrapod limbs and their developmental origins. However, for all that we now understand about the conserved mechanisms of limb development and the development of gross morphological disturbances, little of what is presented in the experimental or medical literature reflects the remarkable diversity resulting from the 450 million year experiment of natural selection. An understanding of conserved and divergent limb morphologies in this new age of genomics and genome engineering promises to reveal more of the developmental potential residing in all limbs and to unravel the mechanisms of evolutionary variation in limb size and shape. In this review, we present the current state of our rapidly advancing understanding of the evolutionary origin of hands and feet and highlight what is known about the mechanisms that shape diverse limbs.This article is part of the themed issue 'Evo-devo in the genomics era, and the origins of morphological diversity'.
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Affiliation(s)
- Aditya Saxena
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA
| | - Matthew Towers
- Bateson Centre, Department of Biomedical Sciences, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Kimberly L. Cooper
- Division of Biological Sciences, University of California San Diego, 9500 Gilman Drive, La Jolla, CA 92093, USA,e-mail:
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Wang S, Stiegler J, Amiot R, Wang X, Du GH, Clark JM, Xu X. Extreme Ontogenetic Changes in a Ceratosaurian Theropod. Curr Biol 2016; 27:144-148. [PMID: 28017609 DOI: 10.1016/j.cub.2016.10.043] [Citation(s) in RCA: 57] [Impact Index Per Article: 7.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/22/2016] [Revised: 10/03/2016] [Accepted: 10/20/2016] [Indexed: 10/20/2022]
Abstract
Ontogenetic variation is documented within many dinosaur species, but extreme ontogenetic changes are rare among dinosaurs, particularly among theropods. Here, we analyze 19 specimens of the Jurassic ceratosaurian theropod Limusaurus inextricabilis, representing six ontogenetic stages based on body size and histological data. Among 78 ontogenetic changes we identify in these specimens, the most unexpected one is the change from fully toothed jaws in the hatchling and juvenile individuals to a completely toothless beaked jaw in the more mature individuals, representing the first fossil record of ontogenetic edentulism among the jawed vertebrates. Jaw morphological data, including those derived from Mi-CT and SR-μCT scanning of Limusaurus specimens, reveal dental alveolar vestiges and indicate that ontogenetic tooth loss in Limusaurus is a gradual, complex process. Our discovery has significant implications for understanding the evolution of the beak, an important feeding structure present in several tetrapod clades, including modern birds. This radical morphological change suggests a dietary shift, probably from omnivory for juvenile Limusaurus to herbivory for adult Limusaurus, which is also supported by additional evidence from gastroliths and stable isotopes. Incorporating new ontogenetic information from Limusaurus into phylogenetic analyses demonstrates surprisingly little effect on its placement when data from different stages are used exclusively, in contrast to previous analyses of tyrannosaurids, but produces subtle differences extending beyond the placement of Limusaurus.
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Affiliation(s)
- Shuo Wang
- Laboratory of Vertebrate Evolution, College of Life Science, Capital Normal University, 105 West 3(rd) Ring Road North, Beijing 100048, China; Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xi-Zhi-Men-Wai Street, Beijing 100044, China.
| | - Josef Stiegler
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Romain Amiot
- CNRS UMR 5276, Université Claude Bernard Lyon 1 and Ecole Normale Supérieure de Lyon, Villeurbanne Cedex 69622, France
| | - Xu Wang
- Key Laboratory of Cenozoic Geology and Environment, Institute of Geology and Geophysics, Chinese Academy of Sciences, 19 Bei-Tu-Cheng-Xi Road, Beijing 100029, China
| | - Guo-Hao Du
- Shanghai Synchrotron Radiation Facility, Shanghai Institute of Applied Physics, Chinese Academy of Sciences, 239 Zhangheng Road, Shanghai 201204, China
| | - James M Clark
- Department of Biological Sciences, The George Washington University, Washington, DC 20052, USA
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, 142 Xi-Zhi-Men-Wai Street, Beijing 100044, China.
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Sullivan C, Xu X. Morphological Diversity and Evolution of the Jugal in Dinosaurs. Anat Rec (Hoboken) 2016; 300:30-48. [DOI: 10.1002/ar.23488] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2016] [Revised: 09/30/2016] [Accepted: 09/30/2016] [Indexed: 11/07/2022]
Affiliation(s)
- Corwin Sullivan
- Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences; Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; 142 Xizhimenwai Dajie Beijing 100044 China
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins of the Chinese Academy of Sciences; Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; 142 Xizhimenwai Dajie Beijing 100044 China
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Diogo R, Guinard G, Diaz RE. Dinosaurs, Chameleons, Humans, and Evo-Devo Path: Linking Étienne Geoffroy's Teratology, Waddington's Homeorhesis, Alberch's Logic of "Monsters," and Goldschmidt Hopeful "Monsters". JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2016; 328:207-229. [PMID: 28422426 DOI: 10.1002/jez.b.22709] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/16/2016] [Revised: 09/29/2016] [Accepted: 10/03/2016] [Indexed: 12/12/2022]
Abstract
Since the rise of evo-devo (evolutionary developmental biology) in the 1980s, few authors have attempted to combine the increasing knowledge obtained from the study of model organisms and human medicine with data from comparative anatomy and evolutionary biology in order to investigate the links between development, pathology, and macroevolution. Fortunately, this situation is slowly changing, with a renewed interest in evolutionary developmental pathology (evo-devo-path) in the past decades, as evidenced by the idea to publish this special, and very timely, issue on "Developmental Evolution in Biomedical Research." As all of us have recently been involved, independently, in works related in some way or another with evolution and developmental anomalies, we decided to join our different perspectives and backgrounds in the present contribution for this special issue. Specifically, we provide a brief historical account on the study of the links between evolution, development, and pathologies, followed by a review of the recent work done by each of us, and then by a general discussion on the broader developmental and macroevolutionary implications of our studies and works recently done by other authors. Our primary aims are to highlight the strength of studying developmental anomalies within an evolutionary framework to understand morphological diversity and disease by connecting the recent work done by us and others with the research done and broader ideas proposed by authors such as Étienne Geoffroy Saint-Hilaire, Waddington, Goldschmidt, Gould, and Per Alberch, among many others to pave the way for further and much needed work regarding abnormal development and macroevolution.
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Affiliation(s)
- Rui Diogo
- Department of Anatomy, College of Medicine, Howard University, Washington, District of Columbia
| | - Geoffrey Guinard
- UMR CNRS 5561, Biogéosciences, Université de Bourgogne, Dijon, France
| | - Raul E Diaz
- Department of Biology, La Sierra University, Riverside, California.,Natural History Museum of Los Angeles County, Los Angeles, California
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Apesteguía S, Smith ND, Juárez Valieri R, Makovicky PJ. An Unusual New Theropod with a Didactyl Manus from the Upper Cretaceous of Patagonia, Argentina. PLoS One 2016; 11:e0157793. [PMID: 27410683 PMCID: PMC4943716 DOI: 10.1371/journal.pone.0157793] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Accepted: 06/02/2016] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Late Cretaceous terrestrial strata of the Neuquén Basin, northern Patagonia, Argentina have yielded a rich fauna of dinosaurs and other vertebrates. The diversity of saurischian dinosaurs is particularly high, especially in the late Cenomanian-early Turonian Huincul Formation, which has yielded specimens of rebacchisaurid and titanosaurian sauropods, and abelisaurid and carcharodontosaurid theropods. Continued sampling is adding to the known vertebrate diversity of this unit. METHODOLOGY/ PRINCIPAL FINDINGS A new, partially articulated mid-sized theropod was found in rocks from the Huincul Formation. It exhibits a unique combination of traits that distinguish it from other known theropods justifying erection of a new taxon, Gualicho shinyae gen. et sp. nov. Gualicho possesses a didactyl manus with the third digit reduced to a metacarpal splint reminiscent of tyrannosaurids, but both phylogenetic and multivariate analyses indicate that didactyly is convergent in these groups. Derived characters of the scapula, femur, and fibula supports the new theropod as the sister taxon of the nearly coeval African theropod Deltadromeus and as a neovenatorid carcharodontosaurian. A number of these features are independently present in ceratosaurs, and Gualicho exhibits an unusual mosaic of ceratosaurian and tetanuran synapomorphies distributed throughout the skeleton. CONCLUSIONS/ SIGNIFICANCE Gualicho shinyae gen. et sp. nov. increases the known theropod diversity of the Huincul Formation and also represents the first likely neovenatorid from this unit. It is the most basal tetatanuran to exhibit common patterns of digit III reduction that evolved independently in a number of other tetanuran lineages. A close relationship with Deltadromaeus from the Kem Kem beds of Niger adds to the already considerable biogeographic similarity between the Huincul Formation and coeval rock units in North Africa.
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Affiliation(s)
- Sebastián Apesteguía
- Área de Paleontología. Fundación de Historia Natural 'Félix de Azara', CEBBAD, Univ. Maimónides, Buenos Aires, Argentina
| | - Nathan D. Smith
- Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, United States of America
| | - Rubén Juárez Valieri
- Secretaría de Cultura, Gobierno de la Provincia de Río Negro, General Roca, Argentina
| | - Peter J. Makovicky
- Section of Earth Sciences, Integrative Research Center, Field Museum of Natural History, Chicago, Illinois, United States of America
- * E-mail:
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Xing L, McKellar RC, Wang M, Bai M, O'Connor JK, Benton MJ, Zhang J, Wang Y, Tseng K, Lockley MG, Li G, Zhang W, Xu X. Mummified precocial bird wings in mid-Cretaceous Burmese amber. Nat Commun 2016; 7:12089. [PMID: 27352215 PMCID: PMC4931330 DOI: 10.1038/ncomms12089] [Citation(s) in RCA: 65] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2016] [Accepted: 05/27/2016] [Indexed: 11/09/2022] Open
Abstract
Our knowledge of Cretaceous plumage is limited by the fossil record itself: compression fossils surrounding skeletons lack the finest morphological details and seldom preserve visible traces of colour, while discoveries in amber have been disassociated from their source animals. Here we report the osteology, plumage and pterylosis of two exceptionally preserved theropod wings from Burmese amber, with vestiges of soft tissues. The extremely small size and osteological development of the wings, combined with their digit proportions, strongly suggests that the remains represent precocial hatchlings of enantiornithine birds. These specimens demonstrate that the plumage types associated with modern birds were present within single individuals of Enantiornithes by the Cenomanian (99 million years ago), providing insights into plumage arrangement and microstructure alongside immature skeletal remains. This finding brings new detail to our understanding of infrequently preserved juveniles, including the first concrete examples of follicles, feather tracts and apteria in Cretaceous avialans.
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Affiliation(s)
- Lida Xing
- State Key Laboratory of Biogeology and Environmental Geology, China University of Geosciences, Beijing 100083, China.,School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
| | - Ryan C McKellar
- Palaeontology, Royal Saskatchewan Museum, Regina, Saskatchewan, Canada S4P 2V7.,Biology Department, University of Regina, Regina, Saskatchewan, Canada S4S 0A2
| | - Min Wang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
| | - Ming Bai
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Jingmai K O'Connor
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
| | - Michael J Benton
- School of Earth Sciences, University of Bristol, Bristol BS8 1RJ, UK
| | - Jianping Zhang
- School of the Earth Sciences and Resources, China University of Geosciences, Beijing 100083, China
| | - Yan Wang
- Institute of Geology and Paleontology, Linyi University, Linyi 276000, China
| | - Kuowei Tseng
- Department of Exercise and Health Science, University of Taipei, Taipei 11153, China
| | - Martin G Lockley
- Dinosaur Tracks Museum, University of Colorado Denver, Denver, Colorado 80217, USA
| | - Gang Li
- Institute of High Energy Physics, Chinese Academy of Science, Beijing 100049, China
| | | | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
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46
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Rauhut OWM, Carrano MT. The theropod dinosaurElaphrosaurus bambergiJanensch, 1920, from the Late Jurassic of Tendaguru, Tanzania. Zool J Linn Soc 2016. [DOI: 10.1111/zoj.12425] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Oliver W. M. Rauhut
- SNSB; Bayerische Staatssammlung für Paläontologie und Geologie; Department of Earth and Environmental Sciences; GeoBioCenter; Ludwig-Maximilians-University; Richard-Wagner-Straße 10 D-80333 München Germany
| | - Matthew T. Carrano
- Department of Paleobiology; Smithsonian Institution; P.O. Box 37012, MRC 121 Washington DC 20013-7012 USA
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A bizarre theropod from the Early Cretaceous of Japan highlighting mosaic evolution among coelurosaurians. Sci Rep 2016; 6:20478. [PMID: 26908367 PMCID: PMC4763874 DOI: 10.1038/srep20478] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2015] [Accepted: 01/05/2016] [Indexed: 11/12/2022] Open
Abstract
Our understanding of coelurosaurian evolution, particularly of bird origins, has been greatly improved, mainly due to numerous recently discovered fossils worldwide. Nearly all these discoveries are referable to the previously known coelurosaurian subgroups. Here, we report a new theropod, Fukuivenator paradoxus, gen. et sp. nov., based on a nearly complete specimen from the Lower Cretaceous Kitadani Formation of the Tetori Group, Fukui, Japan. While Fukuivenator possesses a large number of morphological features unknown in any other theropod, it has a combination of primitive and derived features seen in different theropod subgroups, notably dromaeosaurid dinosaurs. Computed-tomography data indicate that Fukuivenator possesses inner ears whose morphology is intermediate between those of birds and non-avian dinosaurs. Our phylogenetic analysis recovers Fukuivenator as a basally branching maniraptoran theropod, yet is unable to refer it to any known coelurosaurian subgroups. The discovery of Fukuivenator considerably increases the morphological disparity of coelurosaurian dinosaurs and highlights the high levels of homoplasy in coelurosaurian evolution.
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48
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Wang M, Wang X, Wang Y, Zhou Z. A new basal bird from China with implications for morphological diversity in early birds. Sci Rep 2016; 6:19700. [PMID: 26806355 PMCID: PMC4726217 DOI: 10.1038/srep19700] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 12/17/2015] [Indexed: 11/26/2022] Open
Abstract
The Chinese Lower Cretaceous Jehol Group is the second oldest fossil bird-bearing deposit, only surpassed by Archaeopteryx from the German Upper Jurassic Solnhofen Limestones. Here we report a new bird, Chongmingia zhengi gen. et sp. nov., from the Jehol Biota. Phylogenetic analyses indicate that Chongmingia zhengi is basal to the dominant Mesozoic avian clades Enantiornithes and Ornithuromorpha, and represents a new basal avialan lineage. This new discovery adds to our knowledge regarding the phylogenetic differentiation and morphological diversity in early avian evolution. The furcula of Chongmingia is rigid (reducing its efficiency), consequently requiring more power for flight. However, the elongated forelimb and the large deltopectoral crest on the humerus might indicate that the power was available. The unique combination of features present in this species demonstrates that numerous evolutionary experimentations took place in the early evolution of powered flight. The occurrence of gastroliths further confirms that herbivory was common among basal birds. The Jehol birds faced competition with pterosaurs, and occupied sympatric habitats with non-avian theropods, some of which consumed birds. Thus, avialan herbivory may have reduced ecological competition from carnivorous close relatives and other volant vertebrates early in their evolutionary history.
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Affiliation(s)
- Min Wang
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China.,State Key Laboratory of Palaeobiology and Stratigraphy, Nanjing Institute of Geology and Palaeontology, Chinese Academy of Sciences, Nanjing, 210008, China
| | - Xiaoli Wang
- Institute of Geology and Paleontology, Linyi University, Linyi, Shandong 276000, China.,Shandong Tianyu Museum of Nature, Pingyi, Shandong 273300, China
| | - Yan Wang
- Institute of Geology and Paleontology, Linyi University, Linyi, Shandong 276000, China.,Shandong Tianyu Museum of Nature, Pingyi, Shandong 273300, China
| | - Zhonghe Zhou
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, China
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49
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Wang M, Zhou Z, Zhou S. A new basal ornithuromorph bird (Aves: Ornithothoraces) from the Early Cretaceous of China with implication for morphology of early Ornithuromorpha. Zool J Linn Soc 2016. [DOI: 10.1111/zoj.12302] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Min Wang
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences; Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; 142 Xizhimenwai Street Beijing 100044 China
| | - Zhonghe Zhou
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences; Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; 142 Xizhimenwai Street Beijing 100044 China
| | - Shuang Zhou
- Key Laboratory of Vertebrate Evolution and Human Origins of Chinese Academy of Sciences; Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences; 142 Xizhimenwai Street Beijing 100044 China
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50
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Guinard G. Limusaurus inextricabilis(Theropoda: Ceratosauria) gives a hand to evolutionary teratology: a complementary view on avian manual digits identities. Zool J Linn Soc 2015. [DOI: 10.1111/zoj.12329] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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