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Marsh AD, Rowe TB. Anatomy and systematics of the sauropodomorph Sarahsaurus aurifontanalis from the Early Jurassic Kayenta Formation. PLoS One 2018; 13:e0204007. [PMID: 30304035 PMCID: PMC6179219 DOI: 10.1371/journal.pone.0204007] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/04/2017] [Accepted: 09/01/2018] [Indexed: 12/13/2022] Open
Abstract
Sarahsaurus aurifontanalis, from the Kayenta Formation of Arizona, is one of only three sauropodomorph dinosaurs known from the Early Jurassic of North America. It joins Anchisaurus polyzelus, from the older Portland Formation of the Hartford Basin, and Seitaad reussi, from the younger Navajo Sandstone of Utah, in representing the oldest North American sauropodomorphs. If it is true that sauropodomorphs were absent from North America during the Late Triassic, the relationship among these three dinosaurs offers a test of the mechanisms that drove recovery in North American biodiversity following the end-Triassic extinction event. Here we provide the first thorough description of Sarahsaurus aurifontanalis based on completed preparation and computed tomographic imaging of the holotype and referred specimens. With new anatomical data, our phylogenetic analysis supports the conclusion that Sarahsaurus aurifontanalis is nested within the primarily Gondwanan clade Massospondylidae, while agreeing with previous analyses that the three North American sauropodomorphs do not themselves form an exclusive clade. A revised diagnosis and more thorough understanding of the anatomy of Sarahsaurus aurifontanalis support the view that independent dispersal events were at least partly responsible for the recovery in North American vertebrate diversity following a major extinction event.
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Affiliation(s)
- Adam D. Marsh
- The Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, United States of America
- Division of Science and Resource Management, Petrified Forest National Park, Arizona, United States of America
| | - Timothy B. Rowe
- The Jackson School of Geosciences, University of Texas at Austin, Austin, Texas, United States of America
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52
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McPhee BW, Benson RB, Botha-Brink J, Bordy EM, Choiniere JN. A Giant Dinosaur from the Earliest Jurassic of South Africa and the Transition to Quadrupedality in Early Sauropodomorphs. Curr Biol 2018; 28:3143-3151.e7. [DOI: 10.1016/j.cub.2018.07.063] [Citation(s) in RCA: 43] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2018] [Revised: 05/30/2018] [Accepted: 07/24/2018] [Indexed: 10/28/2022]
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53
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Wiersma JP, Irmis RB. A new southern Laramidian ankylosaurid, Akainacephalus johnsoni gen. et sp. nov., from the upper Campanian Kaiparowits Formation of southern Utah, USA. PeerJ 2018; 6:e5016. [PMID: 30065856 PMCID: PMC6063217 DOI: 10.7717/peerj.5016] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2016] [Accepted: 05/28/2018] [Indexed: 11/20/2022] Open
Abstract
A partial ankylosaurid skeleton from the upper Campanian Kaiparowits Formation of southern Utah is recognized as a new taxon, Akainacephalus johnsoni, gen. et sp. nov. The new taxon documents the first record of an associated ankylosaurid skull and postcranial skeleton from the Kaiparowits Formation. Preserved material includes a complete skull, much of the vertebral column, including a complete tail club, a nearly complete synsacrum, several fore- and hind limb elements, and a suite of postcranial osteoderms, making Akainacephalus johnsoni the most complete ankylosaurid from the Late Cretaceous of southern Laramidia. Arrangement and morphology of cranial ornamentation in Akainacephalus johnsoni is strikingly similar to Nodocephalosaurus kirtlandensis and some Asian ankylosaurids (e.g., Saichania chulsanensis, Pinacosaurus grangeri, and Minotaurasaurus ramachandrani); the cranium is densely ornamented with symmetrically arranged and distinctly raised ossified caputegulae which are predominantly distributed across the dorsal and dorsolateral regions of the nasals, frontals, and orbitals. Cranial caputegulae display smooth surface textures with minor pitting and possess a distinct conical to pyramidal morphology which terminates in a sharp apex. Character analysis suggests a close phylogenetic relationship with N. kirtlandensis, M. ramachandrani, Tarchia teresae, and S. chulsanensis, rather than with Late Cretaceous northern Laramidian ankylosaurids (e.g., Euoplocephalus tutus, Anodontosaurus lambei, and Ankylosaurus magniventris). These new data are consistent with evidence for distinct northern and southern biogeographic provinces in Laramidia during the late Campanian. The addition of this new ankylosaurid taxon from southern Utah enhances our understanding of ankylosaurid diversity and evolutionary relationships. Potential implications for the geographical distribution of Late Cretaceous ankylosaurid dinosaurs throughout the Western Interior suggest multiple time-transgressive biogeographic dispersal events from Asia into Laramidia.
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Affiliation(s)
- Jelle P Wiersma
- Department of Geosciences, James Cook University, Townsville, QLD, Australia.,Natural History Museum of Utah, Salt Lake City, UT, USA.,Department of Geology & Geophysics, University of Utah, Salt Lake City, UT, USA
| | - Randall B Irmis
- Natural History Museum of Utah, Salt Lake City, UT, USA.,Department of Geology & Geophysics, University of Utah, Salt Lake City, UT, USA
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54
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Otero A. Forelimb musculature and osteological correlates in Sauropodomorpha (Dinosauria, Saurischia). PLoS One 2018; 13:e0198988. [PMID: 29975691 PMCID: PMC6033415 DOI: 10.1371/journal.pone.0198988] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/26/2017] [Accepted: 05/30/2018] [Indexed: 12/28/2022] Open
Abstract
This contribution presents the forelimb muscular arrangement of sauropodomorph dinosaurs as inferred by comparisons with living archosaurs (crocodiles and birds) following the Extant Phylogenetic Bracket approach. Forty-one muscles were reconstructed, including lower limb and manus musculature, which prior information available was scarce for sauropodomorphs. A strong emphasis was placed on osteological correlates (such as tubercles, ridges and striae) and comparisons with primitive archosauromorphs are included in order to track these correlates throughout the clade. This should help to elucidate how widespread among other archosaurian groups are these osteological correlates identified in Sauropodomorpha. The ultimate goal of this contribution was to provide an exhaustive guide to muscular identification in fossil archosaurs and to offer solid anatomical bases for future studies based on osteology, myology, functional morphology and systematics.
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Affiliation(s)
- Alejandro Otero
- CONICET - División Paleontología de Vertebrados, Museo de La Plata, La Plata, Argentina
- * E-mail: ,
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55
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Xing L, Caldwell MW, Chen R, Nydam RL, Palci A, Simões TR, McKellar RC, Lee MSY, Liu Y, Shi H, Wang K, Bai M. A mid-Cretaceous embryonic-to-neonate snake in amber from Myanmar. SCIENCE ADVANCES 2018; 4:eaat5042. [PMID: 30035227 PMCID: PMC6051735 DOI: 10.1126/sciadv.aat5042] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 03/05/2018] [Accepted: 06/27/2018] [Indexed: 06/08/2023]
Abstract
We present the first known fossilized snake embryo/neonate preserved in early Late Cretaceous (Early Cenomanian) amber from Myanmar, which at the time, was an island arc including terranes from Austral Gondwana. This unique and very tiny snake fossil is an articulated postcranial skeleton, which includes posterior precloacal, cloacal, and caudal vertebrae, and details of squamation and body shape; a second specimen preserves a fragment of shed skin interpreted as a snake. Important details of skeletal ontogeny, including the stage at which snake zygosphene-zygantral joints began to form along with the neural arch lamina, are preserved. The vertebrae show similarities to those of fossil Gondwanan snakes, suggesting a dispersal route of Gondwanan faunas to Laurasia. Finally, the new species is the first Mesozoic snake to be found in a forested environment, indicating greater ecological diversity among early snakes than previously thought.
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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
| | - Michael W. Caldwell
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Rui Chen
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
| | - Randall L. Nydam
- Department of Anatomy, Midwestern University, Glendale, AZ 85308, USA
| | - Alessandro Palci
- South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Tiago R. Simões
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta T6G 2E9, Canada
| | - Ryan C. McKellar
- Royal Saskatchewan Museum, Regina, Saskatchewan S4P 4W7, Canada
- Biology Department, University of Regina, Regina, Saskatchewan S4S 0A2, Canada
| | - Michael S. Y. Lee
- South Australian Museum, North Terrace, Adelaide, South Australia 5000, Australia
- College of Science and Engineering, Flinders University, Adelaide, South Australia, Australia
| | - Ye Liu
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
- Paleo-diary Museum of Natural History, Beijing 100097, China
| | | | - Kuan Wang
- Paleo-diary Museum of Natural History, Beijing 100097, China
| | - Ming Bai
- Key Laboratory of Zoological Systematics and Evolution, Institute of Zoology, Chinese Academy of Sciences, Beijing 100101, China
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56
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The most basal ankylosaurine dinosaur from the Albian-Cenomanian of China, with implications for the evolution of the tail club. Sci Rep 2018; 8:3711. [PMID: 29487376 PMCID: PMC5829254 DOI: 10.1038/s41598-018-21924-7] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/13/2017] [Accepted: 02/13/2018] [Indexed: 11/30/2022] Open
Abstract
The tail club knob is a highly specialized structure thought to characterize a subgroup of the ankylosaurine ankylosaurians, and the oldest documented tail club knob in the fossil record occurred in the Campanian ankylosaurine Pinacosaurus. Here we report a new ankylosaurid Jinyunpelta sinensis, gen. et sp. nov., from the Albian–Cenomanian Liangtoutang Formation, Jinyun County, Zhejiang, China. This is the first definitive and the best preserved ankylosaurid dinosaur ever found in southern China. Jinyunpelta possesses unique cranial features differs from other ankylosaurs including two paranasal apertures level with and posterior to the external naris, a triangular fossa on the anterodorsal edge of the maxilla, an antorbital fossa in the junction between the maxilla, lacrimal and jugal, and an anterior process of the prearticular that lies ventral to the splenial. Our phylogenetic analysis suggests Jinyunpelta as the most basal ankylosaurine dinosaur. Jinyunpelta has a tail club with interlocking caudal vertebrae and a well-developed tail club knob, it represents the oldest and the most basal ankylosaurian known to have a well-developed tail club knob. The new discovery thus demonstrates that a large and highly modified tail club evolved at the base of the ankylosaurine ankylosaurs at least about 100 million years ago.
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57
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Bishop PJ, Clemente CJ, Weems RE, Graham DF, Lamas LP, Hutchinson JR, Rubenson J, Wilson RS, Hocknull SA, Barrett RS, Lloyd DG. Using step width to compare locomotor biomechanics between extinct, non-avian theropod dinosaurs and modern obligate bipeds. J R Soc Interface 2018; 14:rsif.2017.0276. [PMID: 28724627 DOI: 10.1098/rsif.2017.0276] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2017] [Accepted: 06/22/2017] [Indexed: 12/13/2022] Open
Abstract
How extinct, non-avian theropod dinosaurs locomoted is a subject of considerable interest, as is the manner in which it evolved on the line leading to birds. Fossil footprints provide the most direct evidence for answering these questions. In this study, step width-the mediolateral (transverse) distance between successive footfalls-was investigated with respect to speed (stride length) in non-avian theropod trackways of Late Triassic age. Comparable kinematic data were also collected for humans and 11 species of ground-dwelling birds. Permutation tests of the slope on a plot of step width against stride length showed that step width decreased continuously with increasing speed in the extinct theropods (p < 0.001), as well as the five tallest bird species studied (p < 0.01). Humans, by contrast, showed an abrupt decrease in step width at the walk-run transition. In the modern bipeds, these patterns reflect the use of either a discontinuous locomotor repertoire, characterized by distinct gaits (humans), or a continuous locomotor repertoire, where walking smoothly transitions into running (birds). The non-avian theropods are consequently inferred to have had a continuous locomotor repertoire, possibly including grounded running. Thus, features that characterize avian terrestrial locomotion had begun to evolve early in theropod history.
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Affiliation(s)
- P J Bishop
- Geosciences Program, Queensland Museum, Brisbane, Australia .,School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - C J Clemente
- School of Science and Engineering, University of the Sunshine Coast, Maroochydore, Australia.,School of Biological Sciences, University of Queensland, Brisbane, Australia
| | - R E Weems
- Calvert Marine Museum, Solomons, USA.,Paleo Quest, Gainesville, FL, USA
| | - D F Graham
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - L P Lamas
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, UK.,Faculdade de Medicina Veterinária, Universidade de Lisboa, Lisbon, Portugal
| | - J R Hutchinson
- Structure and Motion Laboratory, Royal Veterinary College, Hatfield, UK
| | - J Rubenson
- College of Health and Human Development, Pennsylvania State University, University Park, PA, USA.,School of Human Sciences, University of Western Australia, Crawley, Australia
| | - R S Wilson
- School of Biological Sciences, University of Queensland, Brisbane, Australia
| | - S A Hocknull
- Geosciences Program, Queensland Museum, Brisbane, Australia.,School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - R S Barrett
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia
| | - D G Lloyd
- School of Allied Health Sciences, Griffith University, Gold Coast, Australia.,Innovations in Health Technology, Menzies Health Institute Queensland, Southport, Queensland, Australia.,School of Human Sciences, University of Western Australia, Crawley, Australia
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58
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Bishop PJ, Graham DF, Lamas LP, Hutchinson JR, Rubenson J, Hancock JA, Wilson RS, Hocknull SA, Barrett RS, Lloyd DG, Clemente CJ. The influence of speed and size on avian terrestrial locomotor biomechanics: Predicting locomotion in extinct theropod dinosaurs. PLoS One 2018; 13:e0192172. [PMID: 29466362 PMCID: PMC5821450 DOI: 10.1371/journal.pone.0192172] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2017] [Accepted: 01/17/2018] [Indexed: 12/05/2022] Open
Abstract
How extinct, non-avian theropod dinosaurs moved is a subject of considerable interest and controversy. A better understanding of non-avian theropod locomotion can be achieved by better understanding terrestrial locomotor biomechanics in their modern descendants, birds. Despite much research on the subject, avian terrestrial locomotion remains little explored in regards to how kinematic and kinetic factors vary together with speed and body size. Here, terrestrial locomotion was investigated in twelve species of ground-dwelling bird, spanning a 1,780-fold range in body mass, across almost their entire speed range. Particular attention was devoted to the ground reaction force (GRF), the force that the feet exert upon the ground. Comparable data for the only other extant obligate, striding biped, humans, were also collected and studied. In birds, all kinematic and kinetic parameters examined changed continuously with increasing speed, while in humans all but one of those same parameters changed abruptly at the walk-run transition. This result supports previous studies that show birds to have a highly continuous locomotor repertoire compared to humans, where discrete 'walking' and 'running' gaits are not easily distinguished based on kinematic patterns alone. The influences of speed and body size on kinematic and kinetic factors in birds are developed into a set of predictive relationships that may be applied to extinct, non-avian theropods. The resulting predictive model is able to explain 79-93% of the observed variation in kinematics and 69-83% of the observed variation in GRFs, and also performs well in extrapolation tests. However, this study also found that the location of the whole-body centre of mass may exert an important influence on the nature of the GRF, and hence some caution is warranted, in lieu of further investigation.
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Affiliation(s)
- P. J. Bishop
- Geosciences Program, Queensland Museum, Brisbane, Queensland, Australia
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
- Innovations in Health Technology, Menzies Health Institute Queensland, Gold Coast, Queensland, Australia
| | - D. F. Graham
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
- Innovations in Health Technology, Menzies Health Institute Queensland, Gold Coast, Queensland, Australia
| | - L. P. Lamas
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
- Faculdade de Medicina Veterinária, Universidade de Lisboa, Lisbon, Portugal
| | - J. R. Hutchinson
- Structure and Motion Laboratory, Department of Comparative Biomedical Sciences, Royal Veterinary College, Hatfield, Hertfordshire, United Kingdom
| | - J. Rubenson
- Biomechanics Laboratory, Department of Kinesiology, Pennsylvania State University, University Park, Pennsylvania, United States of America
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - J. A. Hancock
- Murphy Deming College of Health Sciences, Mary Baldwin University, Staunton, Virginia, United States of America
| | - R. S. Wilson
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
| | - S. A. Hocknull
- Geosciences Program, Queensland Museum, Brisbane, Queensland, Australia
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
- Innovations in Health Technology, Menzies Health Institute Queensland, Gold Coast, Queensland, Australia
| | - R. S. Barrett
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
- Innovations in Health Technology, Menzies Health Institute Queensland, Gold Coast, Queensland, Australia
| | - D. G. Lloyd
- School of Allied Health Sciences, Griffith University, Gold Coast, Queensland, Australia
- Innovations in Health Technology, Menzies Health Institute Queensland, Gold Coast, Queensland, Australia
- School of Human Sciences, University of Western Australia, Crawley, Australia
| | - C. J. Clemente
- School of Biological Sciences, The University of Queensland, Brisbane, Queensland, Australia
- School of Science and Engineering, University of the Sunshine Coast, Maroochydore, Queensland, Australia
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59
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Organ C. Biogeography across the ages. Nat Ecol Evol 2018; 2:412-413. [PMID: 29403078 DOI: 10.1038/s41559-018-0486-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Affiliation(s)
- Chris Organ
- Department of Earth Sciences, Department of Microbiology & Immunology, Honors College , Montana State University, Bozeman, MT, 59717, USA.
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60
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Katz O. Extending the scope of Darwin's 'abominable mystery': integrative approaches to understanding angiosperm origins and species richness. ANNALS OF BOTANY 2018; 121:1-8. [PMID: 29040393 PMCID: PMC5786222 DOI: 10.1093/aob/mcx109] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 08/09/2017] [Indexed: 05/04/2023]
Abstract
Background and aims Angiosperms are the most species-rich group of land plants, but their origins and fast and intense diversification still require an explanation. Scope Extending research scopes can broaden theoretical frameworks and lines of evidence that can lead to solving this 'abominable mystery'. Solutions lie in understanding evolutionary trends across taxa and throughout the Phanerozoic, and integration between hypotheses and ideas that are derived from multiple disciplines. Key Findings Descriptions of evolutionary chronologies should integrate between molecular phylogenies, descriptive palaeontology and palaeoecology. New molecular chronologies open new avenues of research of possible Palaeozoic angiosperm ancestors and how they evolved during as many as 200Myr until the emergence of true angiosperms. The idea that 'biodiversity creates biodiversity' requires evidence from past and present ecologies, with changes in herbivory and resource availability throughout the Phanerozoic appearing to be particularly promising. Conclusions Promoting our understanding of angiosperm origins and diversification in particular, and the evolution of biodiversity in general, requires more profound understanding of the ecological past through integrating taxonomic, temporal and ecological scopes.
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Affiliation(s)
- Ofir Katz
- Department of Geography and Environmental Development, Ben-Gurion University of the Negev, Be’er-Sheva, Israel
- The Dead Sea and Arava Science Center, Mt Massada, Tamar Regional Council, Israel
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61
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Chapelle KE, Choiniere JN. A revised cranial description of Massospondylus carinatus Owen (Dinosauria: Sauropodomorpha) based on computed tomographic scans and a review of cranial characters for basal Sauropodomorpha. PeerJ 2018; 6:e4224. [PMID: 29340238 PMCID: PMC5768178 DOI: 10.7717/peerj.4224] [Citation(s) in RCA: 32] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/26/2017] [Accepted: 12/13/2017] [Indexed: 11/20/2022] Open
Abstract
Massospondylus carinatus is a basal sauropodomorph dinosaur from the early Jurassic Elliot Formation of South Africa. It is one of the best-represented fossil dinosaur taxa, known from hundreds of specimens including at least 13 complete or nearly complete skulls. Surprisingly, the internal cranial anatomy of M. carinatus has never been described using computed tomography (CT) methods. Using CT scans and 3D digital representations, we digitally reconstruct the bones of the facial skeleton, braincase, and palate of a complete, undistorted cranium of M. carinatus (BP/1/5241). We describe the anatomical features of the cranial bones, and compare them to other closely related sauropodomorph taxa such as Plateosaurus erlenbergiensis, Lufengosaurus huenei, Sarahsaurus aurifontanalis and Efraasia minor. We identify a suite of character states of the skull and braincase for M. carinatus that sets it apart from other taxa, but these remain tentative due to the lack of comparative sauropodomorph braincase descriptions in the literature. Furthermore, we hypothesize 27 new cranial characters useful for determining relationships in non-sauropodan Sauropodomorpha, delete five pre-existing characters and revise the scores of several existing cranial characters to make more explicit homology statements. All the characters that we hypothesized or revised are illustrated. Using parsimony as an optimality criterion, we then test the relationships of M. carinatus (using BP/1/5241 as a specimen-level exemplar) in our revised phylogenetic data matrix.
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Affiliation(s)
- Kimberley E.J. Chapelle
- Evolutionary Studies Institute and School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
| | - Jonah N. Choiniere
- Evolutionary Studies Institute and School of Geosciences, University of the Witwatersrand, Johannesburg, South Africa
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62
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Vršanský P, OruŘinský R, Aristov D, Wei DD, Vidlička Ľ, Ren D. Temporary deleterious mass mutations relate to originations of cockroach families. Biologia (Bratisl) 2017. [DOI: 10.1515/biolog-2017-0096] [Citation(s) in RCA: 29] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
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63
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Phylogeny mandalas for illustrating the Tree of Life. Mol Phylogenet Evol 2017; 117:168-178. [DOI: 10.1016/j.ympev.2016.11.001] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 10/12/2016] [Accepted: 11/01/2016] [Indexed: 01/01/2023]
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64
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Antinucci M, Risso D. A Matter of Taste: Lineage-Specific Loss of Function of Taste Receptor Genes in Vertebrates. Front Mol Biosci 2017; 4:81. [PMID: 29234667 PMCID: PMC5712339 DOI: 10.3389/fmolb.2017.00081] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2017] [Accepted: 11/13/2017] [Indexed: 12/02/2022] Open
Abstract
Vertebrates can perceive at least five different taste qualities, each of which is thought to have a specific role in the evolution of different species. The avoidance of potentially poisonous foods, which are generally bitter or sour tasting, and the search for more nutritious ones, those with high-fat and high-sugar content, are two of the most well-known examples. The study of taste genes encoding receptors that recognize ligands triggering taste sensations has helped to reconstruct several evolutionary adaptations to dietary changes. In addition, an increasing number of studies have focused on pseudogenes, genomic DNA sequences that have traditionally been considered defunct relatives of functional genes mostly because of the presence of deleterious mutations interrupting their open reading frames. The study of taste receptor pseudogenes has helped to shed light on how the evolutionary history of taste in vertebrates has been the result of a succession of gene gain and loss processes. This dynamic role in evolution has been explained by the "less-is-more" hypothesis, suggesting gene loss as a mechanism of evolutionary change in response to a dietary shift. This mini-review aims at depicting the major lineage-specific loss of function of taste receptor genes in vertebrates, stressing their evolutionary importance and recapitulating signatures of natural selection and their correlations with food habits.
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Affiliation(s)
| | - Davide Risso
- Department of Genome Sciences, University of Washington School of Medicine, Seattle, WA, United States
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65
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McPhee BW, Choiniere JN. The osteology of Pulanesaura eocollum: implications for the inclusivity of Sauropoda (Dinosauria). Zool J Linn Soc 2017. [DOI: 10.1093/zoolinnean/zlx074] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Affiliation(s)
- Blair W McPhee
- Departamento de Biologia, FFCLRP, Universidade de São Paulo, Ribeirão Preto, São Paulo, Brazil
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, Gauteng, South Africa
| | - Jonah N Choiniere
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, Gauteng, South Africa
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66
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Pickering J, Towers M. Inhibition of Shh signalling in the chick wing gives insights into digit patterning and evolution. Development 2017; 143:3514-3521. [PMID: 27702785 PMCID: PMC5087615 DOI: 10.1242/dev.137398] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2016] [Accepted: 08/11/2016] [Indexed: 11/25/2022]
Abstract
In an influential model of pattern formation, a gradient of Sonic hedgehog (Shh) signalling in the chick wing bud specifies cells with three antero-posterior positional values, which give rise to three morphologically different digits by a self-organizing mechanism with Turing-like properties. However, as four of the five digits of the mouse limb are morphologically similar in terms of phalangeal pattern, it has been suggested that self-organization alone could be sufficient. Here, we show that inhibition of Shh signalling at a specific stage of chick wing development results in a pattern of four digits, three of which can have the same number of phalanges. These patterning changes are dependent on a posterior extension of the apical ectodermal ridge, and this also allows the additional digit to arise from the Shh-producing cells of the polarizing region – an ability lost in ancestral theropod dinosaurs. Our analyses reveal that, if the specification of antero-posterior positional values is curtailed, self-organization can then produce several digits with the same number of phalanges. We present a model that may give important insights into how the number of digits and phalanges has diverged during the evolution of avian and mammalian limbs. Highlighted Article: In the chick wing, the relative timing of the specification of antero-posterior positional values and self-organising mechanisms determines digit patterning and identity.
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Affiliation(s)
- Joseph Pickering
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
| | - Matthew Towers
- Bateson Centre, Department of Biomedical Science, University of Sheffield, Western Bank, Sheffield S10 2TN, UK
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67
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Bronzati M, Rauhut OWM. Braincase redescription of Efraasia minor Huene, 1908 (Dinosauria: Sauropodomorpha) from the Late Triassic of Germany, with comments on the evolution of the sauropodomorph braincase. Zool J Linn Soc 2017. [DOI: 10.1093/zoolinnean/zlx029] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022]
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68
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Wiemann J, Yang TR, Sander PN, Schneider M, Engeser M, Kath-Schorr S, Müller CE, Sander PM. Dinosaur origin of egg color: oviraptors laid blue-green eggs. PeerJ 2017; 5:e3706. [PMID: 28875070 PMCID: PMC5580385 DOI: 10.7717/peerj.3706] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Accepted: 07/27/2017] [Indexed: 12/02/2022] Open
Abstract
Protoporphyrin (PP) and biliverdin (BV) give rise to the enormous diversity in avian egg coloration. Egg color serves several ecological purposes, including post-mating signaling and camouflage. Egg camouflage represents a major character of open-nesting birds which accomplish protection of their unhatched offspring against visually oriented predators by cryptic egg coloration. Cryptic coloration evolved to match the predominant shades of color found in the nesting environment. Such a selection pressure for the evolution of colored or cryptic eggs should be present in all open nesting birds and relatives. Many birds are open-nesting, but protect their eggs by continuous brooding, and thus exhibit no or minimal eggshell pigmentation. Their closest extant relatives, crocodiles, protect their eggs by burial and have unpigmented eggs. This phylogenetic pattern led to the assumption that colored eggs evolved within crown birds. The mosaic evolution of supposedly avian traits in non-avian theropod dinosaurs, however, such as the supposed evolution of partially open nesting behavior in oviraptorids, argues against this long-established theory. Using a double-checking liquid chromatography ESI-Q-TOF mass spectrometry routine, we traced the origin of colored eggs to their non-avian dinosaur ancestors by providing the first record of the avian eggshell pigments protoporphyrin and biliverdin in the eggshells of Late Cretaceous oviraptorid dinosaurs. The eggshell parataxon Macroolithus yaotunensis can be assigned to the oviraptor Heyuannia huangi based on exceptionally preserved, late developmental stage embryo remains. The analyzed eggshells are from three Late Cretaceous fluvial deposits ranging from eastern to southernmost China. Reevaluation of these taphonomic settings, and a consideration of patterns in the porosity of completely preserved eggs support an at least partially open nesting behavior for oviraptorosaurs. Such a nest arrangement corresponds with our reconstruction of blue-green eggs for oviraptors. According to the sexual signaling hypothesis, the reconstructed blue-green eggs support the origin of previously hypothesized avian paternal care in oviraptorid dinosaurs. Preserved dinosaur egg color not only pushes the current limits of the vertebrate molecular and associated soft tissue fossil record, but also provides a perspective on the potential application of this unexplored paleontological resource.
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Affiliation(s)
- Jasmina Wiemann
- Division of Palaeontology, Steinmann Institute of Geology, Mineralogy and Palaeontology, University of Bonn, Bonn, Germany.,Department of Geology & Geophysics, Yale University, New Haven, CT, United States of America
| | - Tzu-Ruei Yang
- Division of Palaeontology, Steinmann Institute of Geology, Mineralogy and Palaeontology, University of Bonn, Bonn, Germany
| | - Philipp N Sander
- Life and Medical Sciences Institute, University of Bonn, Bonn, Germany.,Department of Chemistry, University of California, Berkeley, United States of America
| | - Marion Schneider
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, Bonn, Germany
| | - Marianne Engeser
- Kekulé Institute for Organic Chemistry and Biochemistry, University of Bonn, Bonn, Germany
| | | | - Christa E Müller
- Pharmaceutical Institute, Pharmaceutical Chemistry I, University of Bonn, Bonn, Germany
| | - P Martin Sander
- Division of Palaeontology, Steinmann Institute of Geology, Mineralogy and Palaeontology, University of Bonn, Bonn, Germany
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69
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Griffin CT, Stefanic CM, Parker WG, Hungerbühler A, Stocker MR. Sacral anatomy of the phytosaur Smilosuchus adamanensis, with implications for pelvic girdle evolution among Archosauriformes. J Anat 2017; 231:886-905. [PMID: 28836268 DOI: 10.1111/joa.12681] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/13/2017] [Indexed: 11/29/2022] Open
Abstract
The sacrum - consisting of those vertebrae that articulate with the ilia - is the exclusive skeletal connection between the hindlimbs and axial skeleton in tetrapods. Therefore, the morphology of this portion of the vertebral column plays a major role in the evolution of terrestrial locomotion. Whereas most extant reptiles only possess the two plesiomorphic sacral vertebrae, additional vertebrae have been incorporated into the sacrum multiple times independently among early-diverging archosaurian (crocodylians + birds) clades. Phytosauria was a diverse, abundant, and cosmopolitan clade of archosauriforms throughout the Late Triassic, but postcrania of this clade are rarely described and few species-level taxonomic placements of phytosaurian postcranial material are available, potentially hampering knowledge of morphological disparity in the postcranial skeleton among phytosaurs. Here, we describe the sacrum of Smilosuchus adamanensis, a phytosaur recovered from the Upper Triassic Chinle Formation of Arizona. This sacrum consists of the two primordial sacral vertebrae, but has a vertebra incorporated from the trunk into the sacrum (= a dorsosacral) and is therefore the first Late Triassic phytosaur and one of the first non-archosaurian archosauromorphs to be described with more than two sacral vertebrae. Our interpretation of this element as a dorsosacral is justified by the lateral extent of the dorsosacral ribs, clear surfaces of articulation between the distal ends of the dorsosacral ribs and the first primordial sacral ribs, and the scar on the medial surface of each ilium for articulation with each dorsosacral rib. Additionally, we provide the first detailed description of the vertebral junction formed by two anteriorly projecting flanges on the first primordial sacral ribs and their corresponding facets on the centrum of the dorsosacral. Computed tomographic (CT) imaging reveals that the two primordial sacrals are not co-ossified and that the dorsosacral morphology of this specimen is not the result of obvious pathology. We place this incorporation of a trunk vertebra into the phytosaurian sacrum in a broader evolutionary context, with this shift in vertebral identity occurring at least seven times independently among Triassic archosauriforms, including at least three times in early crocodylian-line archosaurs and at least four times among bird-line archosaurs. Additionally, anteriorly projecting flanges of sacral ribs which articulate with the anterior-adjacent centrum have evolved several times in archosauriforms, and we interpret 'shared' sacral ribs (= a sacral rib that articulates with two adjacent sacral centra more or less equally) present in some archosaurian clades as a more extreme example of this morphology. In extant taxa the highly conserved Hox gene family plays a central role in the patterning of the axial skeleton, especially vertebral identity; therefore, the independent incorporation of a trunk vertebra into the sacrum across multiple archosauriform lineages may suggest a homologous underlying developmental mechanism for this evolutionary trend.
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Affiliation(s)
| | - Candice M Stefanic
- Department of Geosciences, Virginia Tech, Blacksburg, VA, USA.,Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY, USA
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Abstract
Predatory theropod dinosaurs can usually be identified as such by features of their jaws, teeth, and postcrania, but different clades of these reptiles differed in their adaptations for prey handling. Inferences about theropod diets and hunting behavior based on functional morphology are sometimes supported by evidence from taphonomic associations with likely prey species, bite marks, gut contents, coprolites, and trackways. Very large theropods like Tyrannosaurus are unlikely to have been pure hunters or scavengers, and probably ate whatever meat they could easily obtain, dead or alive. Theropods were not the only dinosaur hunters, though; other kinds of large reptiles undoubtedly fed on dinosaurs as well The taxonomic composition of dinosaurian predator-prey complexes varies as a function of time and geography, but an ecologically remarkable feature of dinosaurian faunas, as compared with terrestrial mammalian faunas, is the very large size commonly attained by both herbivorous and carnivorous dinosaurs. The K/T extinction event(s) did not end dinosaurian predation, because carnivorous birds remained prominent predators throughout the Cenozoic Era.
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71
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Gorscak E, O'Connor PM. Time-calibrated models support congruency between Cretaceous continental rifting and titanosaurian evolutionary history. Biol Lett 2017; 12:rsbl.2015.1047. [PMID: 27048465 DOI: 10.1098/rsbl.2015.1047] [Citation(s) in RCA: 68] [Impact Index Per Article: 9.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/01/2016] [Indexed: 11/12/2022] Open
Abstract
Recent model-based phylogenetic approaches have expanded upon the incorporation of extinct lineages and their respective temporal information for calibrating divergence date estimates. Here, model-based methods are explored to estimate divergence dates and ancestral ranges for titanosaurian sauropod dinosaurs, an extinct and globally distributed terrestrial clade that existed during the extensive Cretaceous supercontinental break-up. Our models estimate an Early Cretaceous (approx. 135 Ma) South American origin for Titanosauria. The estimated divergence dates are broadly congruent with Cretaceous geophysical models of supercontinental separation and subsequent continental isolation while obviating the invocation of continuous Late Cretaceous continental connections (e.g. ephemeral land bridges). Divergence dates for mid-Cretaceous African and South American sister lineages support semi-isolated subequatorial African faunas in concordance with the gradual northward separation between South America and Africa. Finally, Late Cretaceous Africa may have linked Laurasian lineages with their sister South American lineages, though the current Late Cretaceous African terrestrial fossil record remains meagre.
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Affiliation(s)
- Eric Gorscak
- Department of Biological Sciences, Ohio University, 107 Irvine Hall, Athens, OH 45701, USA Ohio Center for Ecology and Evolutionary Studies, Irvine Hall, Athens, OH 45701, USA
| | - Patrick M O'Connor
- Ohio Center for Ecology and Evolutionary Studies, Irvine Hall, Athens, OH 45701, USA Department of Biomedical Sciences, Ohio University Heritage College of Osteopathic Medicine, 228 Irvine Hall, Athens, OH 45701, USA
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72
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The earliest bird-line archosaurs and the assembly of the dinosaur body plan. Nature 2017; 544:484-487. [PMID: 28405026 DOI: 10.1038/nature22037] [Citation(s) in RCA: 80] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/10/2016] [Accepted: 02/28/2017] [Indexed: 11/08/2022]
Abstract
The relationship between dinosaurs and other reptiles is well established, but the sequence of acquisition of dinosaurian features has been obscured by the scarcity of fossils with transitional morphologies. The closest extinct relatives of dinosaurs either have highly derived morphologies or are known from poorly preserved or incomplete material. Here we describe one of the stratigraphically lowest and phylogenetically earliest members of the avian stem lineage (Avemetatarsalia), Teleocrater rhadinus gen. et sp. nov., from the Middle Triassic epoch. The anatomy of T. rhadinus provides key information that unites several enigmatic taxa from across Pangaea into a previously unrecognized clade, Aphanosauria. This clade is the sister taxon of Ornithodira (pterosaurs and birds) and shortens the ghost lineage inferred at the base of Avemetatarsalia. We demonstrate that several anatomical features long thought to characterize Dinosauria and dinosauriforms evolved much earlier, soon after the bird-crocodylian split, and that the earliest avemetatarsalians retained the crocodylian-like ankle morphology and hindlimb proportions of stem archosaurs and early pseudosuchians. Early avemetatarsalians were substantially more species-rich, widely geographically distributed and morphologically diverse than previously recognized. Moreover, several early dinosauromorphs that were previously used as models to understand dinosaur origins may represent specialized forms rather than the ancestral avemetatarsalian morphology.
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73
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Tickle C, Towers M. Sonic Hedgehog Signaling in Limb Development. Front Cell Dev Biol 2017; 5:14. [PMID: 28293554 PMCID: PMC5328949 DOI: 10.3389/fcell.2017.00014] [Citation(s) in RCA: 108] [Impact Index Per Article: 15.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2016] [Accepted: 02/08/2017] [Indexed: 02/04/2023] Open
Abstract
The gene encoding the secreted protein Sonic hedgehog (Shh) is expressed in the polarizing region (or zone of polarizing activity), a small group of mesenchyme cells at the posterior margin of the vertebrate limb bud. Detailed analyses have revealed that Shh has the properties of the long sought after polarizing region morphogen that specifies positional values across the antero-posterior axis (e.g., thumb to little finger axis) of the limb. Shh has also been shown to control the width of the limb bud by stimulating mesenchyme cell proliferation and by regulating the antero-posterior length of the apical ectodermal ridge, the signaling region required for limb bud outgrowth and the laying down of structures along the proximo-distal axis (e.g., shoulder to digits axis) of the limb. It has been shown that Shh signaling can specify antero-posterior positional values in limb buds in both a concentration- (paracrine) and time-dependent (autocrine) fashion. Currently there are several models for how Shh specifies positional values over time in the limb buds of chick and mouse embryos and how this is integrated with growth. Extensive work has elucidated downstream transcriptional targets of Shh signaling. Nevertheless, it remains unclear how antero-posterior positional values are encoded and then interpreted to give the particular structure appropriate to that position, for example, the type of digit. A distant cis-regulatory enhancer controls limb-bud-specific expression of Shh and the discovery of increasing numbers of interacting transcription factors indicate complex spatiotemporal regulation. Altered Shh signaling is implicated in clinical conditions with congenital limb defects and in the evolution of the morphological diversity of vertebrate limbs.
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Affiliation(s)
- Cheryll Tickle
- Department of Biology and Biochemistry, University of BathBath, UK,*Correspondence: Cheryll Tickle
| | - Matthew Towers
- Department of Biomedical Science, The Bateson Centre, University of SheffieldWestern Bank, Sheffield, UK,Matthew Towers
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74
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MacLaren JA, Anderson PSL, Barrett PM, Rayfield EJ. Herbivorous dinosaur jaw disparity and its relationship to extrinsic evolutionary drivers. PALEOBIOLOGY 2017; 43:15-33. [PMID: 28216798 PMCID: PMC5270766 DOI: 10.1017/pab.2016.31] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Accepted: 07/19/2016] [Indexed: 06/01/2023]
Abstract
Morphological responses of nonmammalian herbivores to external ecological drivers have not been quantified over extended timescales. Herbivorous nonavian dinosaurs are an ideal group to test for such responses, because they dominated terrestrial ecosystems for more than 155 Myr and included the largest herbivores that ever existed. The radiation of dinosaurs was punctuated by several ecologically important events, including extinctions at the Triassic/Jurassic (Tr/J) and Jurassic/Cretaceous (J/K) boundaries, the decline of cycadophytes, and the origin of angiosperms, all of which may have had profound consequences for herbivore communities. Here we present the first analysis of morphological and biomechanical disparity for sauropodomorph and ornithischian dinosaurs in order to investigate patterns of jaw shape and function through time. We find that morphological and biomechanical mandibular disparity are decoupled: mandibular shape disparity follows taxonomic diversity, with a steady increase through the Mesozoic. By contrast, biomechanical disparity builds to a peak in the Late Jurassic that corresponds to increased functional variation among sauropods. The reduction in biomechanical disparity following this peak coincides with the J/K extinction, the associated loss of sauropod and stegosaur diversity, and the decline of cycadophytes. We find no specific correspondence between biomechanical disparity and the proliferation of angiosperms. Continual ecological and functional replacement of pre-existing taxa accounts for disparity patterns through much of the Cretaceous, with the exception of several unique groups, such as psittacosaurids that are never replaced in their biomechanical or morphological profiles.
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Affiliation(s)
- Jamie A MacLaren
- Department of Biology , Universiteit Antwerpen , Campus Drie Eiken , Universiteitsplein , Wilrijk , Antwerp , 2610 , Belgium
| | - Philip S L Anderson
- Department of Animal Biology , University of Illinois at Urbana-Champaign , 515 Morrill Hall , 505 S. Goodwin Ave. , Urbana , Illinois 61801 , U.S.A
| | - Paul M Barrett
- Department of Earth Sciences , Natural History Museum , London , Cromwell Road , London , SW7 5BD , U.K
| | - Emily J Rayfield
- School of Earth Sciences , University of Bristol , 24 Tyndall Avenue , Bristol , BS8 1TQ , U.K
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75
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Nabavizadeh A, Weishampel DB. The Predentary Bone and Its Significance in the Evolution of Feeding Mechanisms in Ornithischian Dinosaurs. Anat Rec (Hoboken) 2016; 299:1358-88. [PMID: 27490958 DOI: 10.1002/ar.23455] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2016] [Revised: 06/11/2016] [Accepted: 06/16/2016] [Indexed: 11/10/2022]
Abstract
The characteristic predentary bone in ornithischian dinosaurs is a unique, unpaired element located at the midline of the mandibular symphysis. Although traditionally thought to only be a plant "nipping" bone, the true functional significance of this bone among feeding mechanisms of ornithischian dinosaurs is poorly known. Recent studies of a select few ornithischian genera have suggested rotation of the mandibular corpora around their long axes relative to their midline joint articulation with the predentary bone. This study aims to re-evaluate these hypotheses as well as provide in-depth qualitative comparative descriptions of predentary bone morphology in ornithischian genera throughout all subclades, including heterodontosaurids, thyreophorans, ornithopods, and marginocephalians. Descriptions evaluate overall shape of the predentary, its articular surfaces contacting the rostral ends of the dentaries, and the morphology of the rostral extent of the dentaries and their midline symphysis. Functionally relevant morphologies in each predentary morphotype are accentuated for further speculation of feeding mechanisms. Three predentary morphotypes are described throughout ornithischian subclades and each plays a unique role in feeding adaptations. Most notably, the predentary likely evolved as a midline axial point of the mandibular symphysis for simultaneous variable movement or rotation of the mandibular corpora in many, but not all, taxa. This simultaneous movement of the hemimandibles would have aided in feeding on both sides of the jaw at once. The function of the predentary as well as other jaw adaptations is discussed for genera throughout all subclades, focusing on both general shape and joint morphology. Anat Rec, 299:1358-1388, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Ali Nabavizadeh
- Department of Biomedical Sciences, Cooper Medical School of Rowan University, Camden, New Jersey.
| | - David B Weishampel
- Johns Hopkins University School of Medicine, Center for Functional Anatomy and Evolution, Baltimore, Maryland
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76
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Baron MG, Norman DB, Barrett PM. Postcranial anatomy ofLesothosaurus diagnosticus(Dinosauria: Ornithischia) from the Lower Jurassic of southern Africa: implications for basal ornithischian taxonomy and systematics. Zool J Linn Soc 2016. [DOI: 10.1111/zoj.12434] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Affiliation(s)
- Matthew G. Baron
- Department of Earth Science; University of Cambridge; Downing Street Cambridge CB2 3EQ UK
- Department of Earth Sciences; The Natural History Museum; Cromwell Road London SW7 5BD UK
| | - David B. Norman
- Department of Earth Science; University of Cambridge; Downing Street Cambridge CB2 3EQ UK
| | - Paul M. Barrett
- Department of Earth Sciences; The Natural History Museum; Cromwell Road London SW7 5BD UK
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77
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Ezcurra MD. The phylogenetic relationships of basal archosauromorphs, with an emphasis on the systematics of proterosuchian archosauriforms. PeerJ 2016; 4:e1778. [PMID: 27162705 PMCID: PMC4860341 DOI: 10.7717/peerj.1778] [Citation(s) in RCA: 116] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2015] [Accepted: 02/18/2016] [Indexed: 11/20/2022] Open
Abstract
The early evolution of archosauromorphs during the Permo-Triassic constitutes an excellent empirical case study to shed light on evolutionary radiations in deep time and the timing and processes of recovery of terrestrial faunas after a mass extinction. However, macroevolutionary studies of early archosauromorphs are currently limited by poor knowledge of their phylogenetic relationships. In particular, one of the main early archosauromorph groups that need an exhaustive phylogenetic study is "Proterosuchia," which as historically conceived includes members of both Proterosuchidae and Erythrosuchidae. A new data matrix composed of 96 separate taxa (several of them not included in a quantitative phylogenetic analysis before) and 600 osteological characters was assembled and analysed to generate a comprehensive higher-level phylogenetic hypothesis of basal archosauromorphs and shed light on the species-level interrelationships of taxa historically identified as proterosuchian archosauriforms. The results of the analysis using maximum parsimony include a polyphyletic "Prolacertiformes" and "Protorosauria," in which the Permian Aenigmastropheus and Protorosaurus are the most basal archosauromorphs. The enigmatic choristoderans are either found as the sister-taxa of all other lepidosauromorphs or archosauromorphs, but consistently placed within Sauria. Prolacertids, rhynchosaurs, allokotosaurians and tanystropheids are the major successive sister clades of Archosauriformes. The Early Triassic Tasmaniosaurus is recovered as the sister-taxon of Archosauriformes. Proterosuchidae is unambiguosly restricted to five species that occur immediately after and before the Permo-Triassic boundary, thus implying that they are a short-lived "disaster" clade. Erythrosuchidae is composed of eight nominal species that occur during the Early and Middle Triassic. "Proterosuchia" is polyphyletic, in which erythrosuchids are more closely related to Euparkeria and more crownward archosauriforms than to proterosuchids, and several species are found widespread along the archosauromorph tree, some being nested within Archosauria (e.g., "Chasmatosaurus ultimus," Youngosuchus). Doswelliids and proterochampsids are recovered as more closely related to each other than to other archosauromorphs, forming a large clade (Proterochampsia) of semi-aquatic to aquatic forms that includes the bizarre genus Vancleavea. Euparkeria is one of the sister-taxa of the clade composed of proterochampsians and archosaurs. The putative Indian archosaur Yarasuchus is recovered in a polytomy with Euparkeria and more crownward archosauriforms, and as more closely related to the Russian Dongusuchus than to other species. Phytosaurs are recovered as the sister-taxa of all other pseudosuchians, thus being nested within Archosauria.
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Affiliation(s)
- Martín D. Ezcurra
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
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78
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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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79
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Fong RK, LeBlanc AR, Berman DS, Reisz RR. Dental histology ofCoelophysis bauriand the evolution of tooth attachment tissues in early dinosaurs. J Morphol 2016; 277:916-24. [DOI: 10.1002/jmor.20545] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Revised: 03/16/2016] [Accepted: 03/25/2016] [Indexed: 11/11/2022]
Affiliation(s)
- Raymond K.M. Fong
- Department of Biology; University of Toronto; Mississauga Ontario L5L 1C6 Canada
| | - Aaron R.H. LeBlanc
- Department of Biology; University of Toronto; Mississauga Ontario L5L 1C6 Canada
| | - David S. Berman
- Vertebrate Paleontology, Carnegie Museum of Natural History; Pittsburgh Pennsylvania
| | - Robert R. Reisz
- Department of Biology; University of Toronto; Mississauga Ontario L5L 1C6 Canada
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80
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Abstract
AbstractThe purposes of classification and taxonomy are reviewed. Using examples from fields ranging from paleontology to planetology, I argue that non-exclusive classifications, which allow Pluto to be considered both a planet and a TNO, provide the most desirable approach to progress in our science.
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81
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Chiarenza AA, Cau A. A large abelisaurid (Dinosauria, Theropoda) from Morocco and comments on the Cenomanian theropods from North Africa. PeerJ 2016; 4:e1754. [PMID: 26966675 PMCID: PMC4782726 DOI: 10.7717/peerj.1754] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2016] [Accepted: 02/12/2016] [Indexed: 11/20/2022] Open
Abstract
We describe the partially preserved femur of a large-bodied theropod dinosaur from the Cenomanian “Kem Kem Compound Assemblage” (KKCA) of Morocco. The fossil is housed in the Museo Geologico e Paleontologico “Gaetano Giorgio Gemmellaro” in Palermo (Italy). The specimen is compared with the theropod fossil record from the KKCA and coeval assemblages from North Africa. The combination of a distally reclined head, a not prominent trochanteric shelf, distally placed lesser trochanter of stout, alariform shape, a stocky shaft with the fourth trochanter placed proximally, and rugose muscular insertion areas in the specimen distinguishes it from Carcharodontosaurus, Deltadromeus and Spinosaurus and supports referral to an abelisaurid. The estimated body size for the individual from which this femur was derived is comparable to Carnotaurus and Ekrixinatosaurus (up to 9 meters in length and 2 tons in body mass). This find confirms that abelisaurids had reached their largest body size in the “middle Cretaceous,” and that large abelisaurids coexisted with other giant theropods in Africa. We review the taxonomic status of the theropods from the Cenomanian of North Africa, and provisionally restrict the Linnean binomina Carcharodontosaurus iguidensis and Spinosaurus aegyptiacus to the type specimens. Based on comparisons among the theropod records from the Aptian-Cenomanian of South America and Africa, a partial explanation for the so-called “Stromer’s riddle” (namely, the coexistence of many large predatory dinosaurs in the “middle Cretaceous” record from North Africa) is offered in term of taphonomic artifacts among lineage records that were ecologically and environmentally non-overlapping. Although morphofunctional and stratigraphic evidence supports an ecological segregation between spinosaurids and the other lineages, the co-occurrence of abelisaurids and carcharodontosaurids, two groups showing several craniodental convergences that suggest direct resource competition, remains to be explained.
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Affiliation(s)
| | - Andrea Cau
- Earth, Life and Environmental Sciences, University of Bologna, Bologna, Italy; Geological and Palaeontological Museum "G. Capellini,"Bologna, Italy
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Lloyd GT. Estimating morphological diversity and tempo with discrete character-taxon matrices: implementation, challenges, progress, and future directions. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12746] [Citation(s) in RCA: 128] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Affiliation(s)
- Graeme T. Lloyd
- Department of Biological Sciences; Faculty of Science; Macquarie University; NSW 2109 Australia
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84
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He Y, Makovicky PJ, Wang K, Chen S, Sullivan C, Han F, Xu X. A New Leptoceratopsid (Ornithischia, Ceratopsia) with a Unique Ischium from the Upper Cretaceous of Shandong Province, China. PLoS One 2015; 10:e0144148. [PMID: 26701114 PMCID: PMC4689537 DOI: 10.1371/journal.pone.0144148] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2015] [Accepted: 11/12/2015] [Indexed: 11/30/2022] Open
Abstract
The partial skeleton of a leptoceratopsid dinosaur, Ischioceratops zhuchengensis gen. et sp. nov., was excavated from the bone-beds of the Upper Cretaceous Wangshi Group of Zhucheng, Shandong Province, China. This fossil represents the second leptoceratopsid dinosaur specimen recovered from the Kugou locality, a highly productive site in Zhucheng. The ischium of the new taxon is morphologically unique among known Dinosauria, flaring gradually to form an obturator process in its middle portion and resembling the shaft of a recurve bow. An elliptical fenestra perforates the obturator process, and the distal end of the shaft forms an axehead-shaped expansion. The discovery of Ischioceratops increases the known taxonomic diversity and morphological disparity of the Leptoceratopsidae.
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Affiliation(s)
- Yiming He
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Palaeontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- University of Chinese Academy of Sciences, Beijing, China
- * E-mail:
| | - Peter J. Makovicky
- Department of Geology, The Field Museum, Chicago, United States of America
| | - Kebai Wang
- Zhucheng Dinosaur Museum, Zhucheng, Shandong, China
| | - Shuqing Chen
- Zhucheng Dinosaur Museum, Zhucheng, Shandong, China
| | - Corwin Sullivan
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Palaeontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
| | - Fenglu Han
- School of Earth Sciences, China University of Geosciences, Wuhan, China
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Palaeontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
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85
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Boyd CA. The systematic relationships and biogeographic history of ornithischian dinosaurs. PeerJ 2015; 3:e1523. [PMID: 26713260 PMCID: PMC4690359 DOI: 10.7717/peerj.1523] [Citation(s) in RCA: 72] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 11/30/2015] [Indexed: 11/23/2022] Open
Abstract
The systematic relationships of taxa traditionally referred to as 'basal ornithopods' or 'hypsilophodontids' remain poorly resolved since it was discovered that these taxa are not a monophyletic group, but rather a paraphyletic set of neornithischian taxa. Thus, even as the known diversity of these taxa has dramatically increased over the past two decades, our knowledge of their placement relative to each other and the major ornithischian subclades remained incomplete. This study employs the largest phylogenetic dataset yet compiled to assess basal ornithischian relationships (255 characters for 65 species level terminal taxa). The resulting strict consensus tree is the most well-resolved, stratigraphically consistent hypothesis of basal ornithischian relationships yet hypothesized. The only non-iguanodontian ornithopod (=basal ornithopod) recovered in this analysis is Hypsilophodon foxii. The majority of former 'hypsilophodontid' taxa are recovered within a single clade (Parksosauridae) that is situated as the sister-taxon to Cerapoda. The Parksosauridae is divided between two subclades, the Orodrominae and the Thescelosaurinae. This study does not recover a clade consisting of the Asian taxa Changchunsaurus, Haya, and Jeholosaurus (=Jeholosauridae). Rather, the former two taxa are recovered as basal members of Thescelosaurinae, while the latter taxon is recovered in a clade with Yueosaurus near the base of Neornithischia.The endemic South American clade Elasmaria is recovered within the Thescelosaurinae as the sister taxon to Thescelosaurus. This study supports the origination of Dinosauria and the early diversification of Ornithischia within Gondwana. Neornithischia first arose in Africa by the Early Jurassic before dispersing to Asia before the late Middle Jurassic, where much of the diversification among non-cerapodan neornithischians occurred. Under the simplest scenario the Parksosauridae originated in North America, with at least two later dispersals to Asia and one to South America. However, when ghost lineages are considered, an alternate dispersal hypothesis has thescelosaurines dispersing from Asia into South America (via North America) during the Early Cretaceous, then back into North America in the latest Cretaceous. The latter hypothesis may explain the dominance of orodromine taxa prior to the Maastrichtian in North America and the sudden appearance and wide distribution of thescelosaurines in North America beginning in the early Maastrichtian. While the diversity of parksosaurids has greatly increased over the last fifteen years, a ghost lineage of over 40 myr is present between the base of Parksosauridae and Cerapoda, indicating that much of the early history and diversity of this clade is yet to be discovered. This new phylogenetic hypothesis provides a comprehensive framework for testing further hypotheses regarding evolutionary patterns and processes within Ornithischia.
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Affiliation(s)
- Clint A. Boyd
- North Dakota Geological Survey, Bismarck, ND, United States
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86
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Porro LB, Witmer LM, Barrett PM. Digital preparation and osteology of the skull of Lesothosaurus diagnosticus (Ornithischia: Dinosauria). PeerJ 2015; 3:e1494. [PMID: 26713245 PMCID: PMC4690377 DOI: 10.7717/peerj.1494] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2015] [Accepted: 11/22/2015] [Indexed: 11/20/2022] Open
Abstract
Several skulls of the ornithischian dinosaur Lesothosaurus diagnosticus (Lower Jurassic, southern Africa) are known, but all are either incomplete, deformed, or incompletely prepared. This has hampered attempts to provide a comprehensive description of skull osteology in this crucial early dinosaurian taxon. Using visualization software, computed tomographic scans of the Lesothosaurus syntypes were digitally segmented to remove matrix, and identify and separate individual cranial and mandibular bones, revealing new anatomical details such as sutural morphology and the presence of several previously undescribed elements. Together with visual inspection of exposed skull bones, these CT data enable a complete description of skull anatomy in this taxon. Comparisons with our new data suggest that two specimens previously identified as Lesothosaurus sp. (MNHN LES 17 and MNHN LES 18) probably represent additional individuals of Lesothosaurus diagnosticus.
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Affiliation(s)
- Laura B Porro
- Department of Comparative Biomedical Sciences, Royal Veterinary College , Hatfield , United Kingdom
| | - Lawrence M Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University , Athens, OH , United States
| | - Paul M Barrett
- Department of Earth Sciences, Natural History Museum , London , United Kingdom
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87
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Leahey LG, Molnar RE, Carpenter K, Witmer LM, Salisbury SW. Cranial osteology of the ankylosaurian dinosaur formerly known as Minmi sp. (Ornithischia: Thyreophora) from the Lower Cretaceous Allaru Mudstone of Richmond, Queensland, Australia. PeerJ 2015; 3:e1475. [PMID: 26664806 PMCID: PMC4675105 DOI: 10.7717/peerj.1475] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2015] [Accepted: 11/16/2015] [Indexed: 11/30/2022] Open
Abstract
Minmi is the only known genus of ankylosaurian dinosaur from Australia. Seven specimens are known, all from the Lower Cretaceous of Queensland. Only two of these have been described in any detail: the holotype specimen Minmi paravertebra from the Bungil Formation near Roma, and a near complete skeleton from the Allaru Mudstone on Marathon Station near Richmond, preliminarily referred to a possible new species of Minmi. The Marathon specimen represents one of the world’s most complete ankylosaurian skeletons and the best-preserved dinosaurian fossil from eastern Gondwana. Moreover, among ankylosaurians, its skull is one of only a few in which the majority of sutures have not been obliterated by dermal ossifications or surface remodelling. Recent preparation of the Marathon specimen has revealed new details of the palate and narial regions, permitting a comprehensive description and thus providing new insights cranial osteology of a basal ankylosaurian. The skull has also undergone computed tomography, digital segmentation and 3D computer visualisation enabling the reconstruction of its nasal cavity and endocranium. The airways of the Marathon specimen are more complicated than non-ankylosaurian dinosaurs but less so than derived ankylosaurians. The cranial (brain) endocast is superficially similar to those of other ankylosaurians but is strongly divergent in many important respects. The inner ear is extremely large and unlike that of any dinosaur yet known. Based on a high number of diagnostic differences between the skull of the Marathon specimen and other ankylosaurians, we consider it prudent to assign this specimen to a new genus and species of ankylosaurian. Kunbarrasaurus ieversi gen. et sp. nov. represents the second genus of ankylosaurian from Australia and is characterised by an unusual melange of both primitive and derived characters, shedding new light on the evolution of the ankylosaurian skull.
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Affiliation(s)
- Lucy G Leahey
- School of Biological Sciences, University of Queensland , Brisbane, Queensland , Australia
| | - Ralph E Molnar
- University of California Museum of Paleontology , Berkeley, CA , USA
| | | | - Lawrence M Witmer
- Department of Biomedical Sciences, Heritage College of Osteopathic Medicine, Ohio University , Athens, OH , USA
| | - Steven W Salisbury
- School of Biological Sciences, University of Queensland , Brisbane, Queensland , Australia
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88
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Nesbitt SJ, Flynn JJ, Pritchard AC, Parrish JM, Ranivoharimanana L, Wyss AR. Postcranial Osteology ofAzendohsaurus madagaskarensis(?Middle to Upper Triassic, Isalo Group, Madagascar) and its Systematic Position Among Stem Archosaur Reptiles. BULLETIN OF THE AMERICAN MUSEUM OF NATURAL HISTORY 2015. [DOI: 10.1206/amnb-899-00-1-126.1] [Citation(s) in RCA: 53] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
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89
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Frazão A, da Silva HR, Russo CADM. The Gondwana Breakup and the History of the Atlantic and Indian Oceans Unveils Two New Clades for Early Neobatrachian Diversification. PLoS One 2015; 10:e0143926. [PMID: 26618546 PMCID: PMC4664409 DOI: 10.1371/journal.pone.0143926] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2015] [Accepted: 11/11/2015] [Indexed: 11/20/2022] Open
Abstract
The largest anuran diversity belongs to the Neobatrachia, which harbor more than five thousand extant species. Here, we propose a new hypothesis for the historical aspects of the neobatrachian evolution with a formal biogeographical analysis. We selected 12 genes for 144 neobatrachian genera and four archaeobatrachian outgroups and performed a phylogenetic analysis using a maximum likelihood algorithm with the rapid bootstrap test. We also estimated divergence times for major lineages using a relaxed uncorrelated clock method. According to our time scale, the diversification of crown Neobatrachia began around the end of the Early Cretaceous. Our phylogenetic tree suggests that the first split of Neobatrachia is related to the geological events in the Atlantic and Indian Oceans. Hence, we propose names for these clades that indicate this connection, i.e., Atlanticanura and Indianura. The Atlanticanura is composed of three major neobatrachian lineages: Heleophrynidae, Australobatrachia and Nobleobatrachia. On the other hand, the Indianura consists of two major lineages: Sooglossoidea and Ranoides. The biogeographical analysis indicates that many neobatrachian splits occurred as a result of geological events such as the separation between South America and Africa, between India and the Seychelles, and between Australia and South America.
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Affiliation(s)
- Annelise Frazão
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
| | - Hélio Ricardo da Silva
- Departamento de Biologia Animal, Instituto de Biologia, Universidade Federal Rural do Rio de Janeiro, Seropédica, Rio de Janeiro, Brazil
| | - Claudia Augusta de Moraes Russo
- Departamento de Genética, Instituto de Biologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro, Brazil
- * E-mail:
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90
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Elevated Extinction Rates as a Trigger for Diversification Rate Shifts: Early Amniotes as a Case Study. Sci Rep 2015; 5:17104. [PMID: 26592209 PMCID: PMC4655484 DOI: 10.1038/srep17104] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2015] [Accepted: 10/26/2015] [Indexed: 11/08/2022] Open
Abstract
Tree shape analyses are frequently used to infer the location of shifts in diversification rate within the Tree of Life. Many studies have supported a causal relationship between shifts and temporally coincident events such as the evolution of “key innovations”. However, the evidence for such relationships is circumstantial. We investigated patterns of diversification during the early evolution of Amniota from the Carboniferous to the Triassic, subjecting a new supertree to analyses of tree balance in order to infer the timing and location of diversification shifts. We investigated how uneven origination and extinction rates drive diversification shifts, and use two case studies (herbivory and an aquatic lifestyle) to examine whether shifts tend to be contemporaneous with evolutionary novelties. Shifts within amniotes tend to occur during periods of elevated extinction, with mass extinctions coinciding with numerous and larger shifts. Diversification shifts occurring in clades that possess evolutionary innovations do not coincide temporally with the appearance of those innovations, but are instead deferred to periods of high extinction rate. We suggest such innovations did not cause increases in the rate of cladogenesis, but allowed clades to survive extinction events. We highlight the importance of examining general patterns of diversification before interpreting specific shifts.
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91
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Kaiser G, Dyke G. The development of flight surfaces on the avian wing. BIOL BULL+ 2015. [DOI: 10.1134/s1062359015070067] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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92
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Cerda IA, Casal GA, Martinez RD, Ibiricu LM. Histological evidence for a supraspinous ligament in sauropod dinosaurs. ROYAL SOCIETY OPEN SCIENCE 2015; 2:150369. [PMID: 26587248 PMCID: PMC4632520 DOI: 10.1098/rsos.150369] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 07/24/2015] [Accepted: 09/29/2015] [Indexed: 06/05/2023]
Abstract
Supraspinous ossified rods have been reported in the sacra of some derived sauropod dinosaurs. Although different hypotheses have been proposed to explain the origin of this structure, histological evidence has never been provided to support or reject any of them. In order to establish its origin, we analyse and characterize the microstructure of the supraspinous rod of two sauropod dinosaurs from the Upper Cretaceous of Argentina. The supraspinous ossified rod is almost entirely formed by dense Haversian bone. Remains of primary bone consist entirely of an avascular tissue composed of two types of fibre-like structures, which are coarse and longitudinally (parallel to the main axis of the element) oriented. These structures are differentiated on the basis of their optical properties under polarized light. Very thin fibrous strands are also observed in some regions. These small fibres are all oriented parallel to one another but perpendicular to the element main axis. Histological features of the primary bone tissue indicate that the sacral supraspinous rod corresponds to an ossified supraspinous ligament. The formation of this structure appears to have been a non-pathological metaplastic ossification, possibly induced by the continuous tensile forces applied to the element.
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Affiliation(s)
- Ignacio A Cerda
- CONICET-Instituto de Investigación en Paleobiología y Geología , Universidad Nacional de Río Negro , Museo Carlos Ameghino, Belgrano 1700, Paraje Pichi Ruca (predio Marabunta) 8300, Cipolletti, Río Negro, Argentina
| | - Gabriel A Casal
- Laboratorio de Paleovertebrados , Universidad Nacional de la Patagonia San Juan Bosco , Ruta Prov. N° 1, Km 4, Comodoro Rivadavia (C.P. 9000), Chubut, Argentina
| | - Rubén D Martinez
- Laboratorio de Paleovertebrados , Universidad Nacional de la Patagonia San Juan Bosco , Ruta Prov. N° 1, Km 4, Comodoro Rivadavia (C.P. 9000), Chubut, Argentina
| | - Lucio M Ibiricu
- CONICET-Centro Nacional Patagónico , Blvd. Alte. Brown 2915, Puerto Madryn, Argentina
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93
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Houssaye A, Waskow K, Hayashi S, Cornette R, Lee AH, Hutchinson JR. Biomechanical evolution of solid bones in large animals: a microanatomical investigation. Biol J Linn Soc Lond 2015. [DOI: 10.1111/bij.12660] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Alexandra Houssaye
- Département Ecologie et Gestion de la Biodiversité; UMR 7179, CNRS/Muséum National d'Histoire Naturelle; 57 rue Cuvier, CP-55 Paris 75000 France
| | - Katja Waskow
- Steinmann Institut für Geologie; Mineralogie und Paläontologie; Universität Bonn; Nussallee 8 Bonn 53115 Germany
| | - Shoji Hayashi
- Osaka Museum of Natural History; Higashi-sumiyoshi-ku Osaka 546-0034 Japan
| | - Raphaël Cornette
- UMR CNRS/MNHN/UPMC/EPHE 7205; Institut de Systématique, Evolution, Biodiversité (ISYEB); Muséum National d'Histoire Naturelle; 45 rue Buffon Paris 75005 France
| | - Andrew H. Lee
- Department of Anatomy; Midwestern University; 19555 N 59th Avenue Glendale AZ 85308 USA
| | - John R. Hutchinson
- Department of Comparative Biomedical Sciences; Structure and Motion Laboratory; The Royal Veterinary College; Hawkshead Lane Hatfield AL9 7TA UK
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94
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Abstract
Tooth morphology and development can provide valuable insights into the feeding behaviour and evolution of extinct organisms. The teeth of Theropoda, the only clade of predominantly predatory dinosaurs, are characterized by ziphodonty, the presence of serrations (denticles) on their cutting edges. Known today only in varanid lizards, ziphodonty is much more pervasive in the fossil record. Here we present the first model for the development of ziphodont teeth in theropods through histological, SEM, and SR-FTIR analyses, revealing that structures previously hypothesized to prevent tooth breakage instead first evolved to shape and maintain the characteristic denticles through the life of the tooth. We show that this novel complex of dental morphology and tissues characterizes Theropoda, with the exception of species with modified feeding behaviours, suggesting that these characters are important for facilitating the hypercarnivorous diet of most theropods. This adaptation may have played an important role in the initial radiation and subsequent success of theropods as terrestrial apex predators.
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95
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Qadri MAJ, Cook RG. Experimental Divergences in the Visual Cognition of Birds and Mammals. COMPARATIVE COGNITION & BEHAVIOR REVIEWS 2015; 10:73-105. [PMID: 26207154 PMCID: PMC4507827 DOI: 10.3819/ccbr.2015.100004] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
The comparative analysis of visual cognition across classes of animals yields important information regarding underlying cognitive and neural mechanisms involved with this foundational aspect of behavior. Birds, and pigeons specifically, have been an important source and model for this comparison, especially in relation to mammals. During these investigations, an extensive number of experiments have found divergent results in how pigeons and humans process visual information. Four areas of these divergences are collected, reviewed, and analyzed. We examine the potential contribution and limitations of experimental, spatial, and attentional factors in the interpretation of these findings and their implications for mechanisms of visual cognition in birds and mammals. Recommendations are made to help advance these comparisons in service of understanding the general principles by which different classes and species generate representations of the visual world.
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96
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VanBuren CS, Campione NE, Evans DC. Head size, weaponry, and cervical adaptation: Testing craniocervical evolutionary hypotheses in Ceratopsia. Evolution 2015; 69:1728-44. [PMID: 26095296 DOI: 10.1111/evo.12693] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2014] [Revised: 04/29/2015] [Accepted: 05/19/2015] [Indexed: 11/28/2022]
Abstract
The anterior cervical vertebrae form the skeletal connection between the cranial and postcranial skeletons in higher tetrapods. As a result, the morphology of the atlas-axis complex is likely to be shaped by selection pressures acting on either the head or neck. The neoceratopsian (Reptilia:Dinosauria) syncervical represents one of the most highly modified atlas-axis regions in vertebrates, being formed by the complete coalescence of the three most anterior cervical vertebrae. In ceratopsids, the syncervical has been hypothesized to be an adaptation to support a massive skull, or to act as a buttress during intraspecific head-to-head combat. Here, we test these functional/adaptive hypotheses within a phylogenetic framework and critically examine the previously proposed methods for quantifying relative head size in the fossil record for the first time. Results indicate that neither the evolution of cranial weaponry nor large head size correlates with the origin of cervical fusion in ceratopsians, and we, therefore, reject both adaptive hypotheses for the origin of the syncervical. Anterior cervical fusion has evolved independently in a number of amniote clades, and further research on extant groups with this peculiar anatomy is needed to understand the evolutionary basis for cervical fusion in Neoceratopsia.
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Affiliation(s)
- Collin S VanBuren
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada. .,Department of earth Sciences, University of Cambridge, Downing Street, Cambridge, CB2 3EQ, United Kingdom.
| | - Nicolás E Campione
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada.,Department of Earth Sciences (Palaeobiology), University of Uppsala, Villavägen 16, SE-752 36, Uppsala, Sweden.,Department of Organismal Biology (Subdepartment of Evolution and Development), Norbyvägen 18A, SE-752 36, Uppsala, Sweden
| | - David C Evans
- Department of Ecology and Evolutionary Biology, University of Toronto, 25 Willcocks Street, Toronto, Ontario, M5S 3B2, Canada.,Department of Natural History, Royal Ontario Museum, 100 Queen's Park, Toronto, Ontario, Canada, M5S 2C6
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97
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Otero A, Krupandan E, Pol D, Chinsamy A, Choiniere J. A new basal sauropodiform from South Africa and the phylogenetic relationships of basal sauropodomorphs. Zool J Linn Soc 2015. [DOI: 10.1111/zoj.12247] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Alejandro Otero
- Consejo Nacional de Investigaciones Científicas y Técnicas (CONICET); División Paleontología de Vertebrados; Museo de La Plata; Paseo del Bosque s/n; 1900 La Plata Argentina
- Evolutionary Studies Institute; Centre of Excellence in Palaeosciences; University of the Witwatersrand; Private Bag 3 Johannesburg Gauteng 2050 South Africa
| | - Emil Krupandan
- Biological Sciences Department; University of Cape Town; Private Bag Rondebosch Cape Town South Africa
| | - Diego Pol
- CONICET; Museo Paleontológico Egidio Feruglio; Av. Fontana 140 9100 Trelew Argentina
| | - Anusuya Chinsamy
- Biological Sciences Department; University of Cape Town; Private Bag Rondebosch Cape Town South Africa
| | - Jonah Choiniere
- Evolutionary Studies Institute; Centre of Excellence in Palaeosciences; University of the Witwatersrand; Private Bag 3 Johannesburg Gauteng 2050 South Africa
- NRF/Centre of Excellence in Palaeosciences; University of the Witwatersrand; Private Bag 3 Johannesburg Gauteng 2050 South Africa
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98
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Peyre de Fabrègues C, Allain R, Barriel V. Root causes of phylogenetic incongruence observed within basal sauropodomorph interrelationships. Zool J Linn Soc 2015. [DOI: 10.1111/zoj.12290] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Claire Peyre de Fabrègues
- Muséum National d'Histoire Naturelle, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P, UMR 7207); Sorbonne Universités-MNHN; CNRS, UPMC, 57 rue Cuvier, CP 38 F-75005 Paris France
| | - Ronan Allain
- Muséum National d'Histoire Naturelle, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P, UMR 7207); Sorbonne Universités-MNHN; CNRS, UPMC, 57 rue Cuvier, CP 38 F-75005 Paris France
| | - Véronique Barriel
- Muséum National d'Histoire Naturelle, Centre de Recherche sur la Paléobiodiversité et les Paléoenvironnements (CR2P, UMR 7207); Sorbonne Universités-MNHN; CNRS, UPMC, 57 rue Cuvier, CP 38 F-75005 Paris France
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99
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Varricchio DJ, Balanoff AM, Norell MA. Reidentification of avian embryonic remains from the cretaceous of mongolia. PLoS One 2015; 10:e0128458. [PMID: 26030147 PMCID: PMC4452496 DOI: 10.1371/journal.pone.0128458] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/27/2015] [Indexed: 11/28/2022] Open
Abstract
Embryonic remains within a small (4.75 by 2.23 cm) egg from the Late Cretaceous, Mongolia are here re-described. High-resolution X-ray computed tomography (HRCT) was used to digitally prepare and describe the enclosed embryonic bones. The egg, IGM (Mongolian Institute for Geology, Ulaanbaatar) 100/2010, with a three-part shell microstructure, was originally assigned to Neoceratopsia implying extensive homoplasy among eggshell characters across Dinosauria. Re-examination finds the forelimb significantly longer than the hindlimbs, proportions suggesting an avian identification. Additional, postcranial apomorphies (strut-like coracoid, cranially located humeral condyles, olecranon fossa, slender radius relative to the ulna, trochanteric crest on the femur, and ulna longer than the humerus) identify the embryo as avian. Presence of a dorsal coracoid fossa and a craniocaudally compressed distal humerus with a strongly angled distal margin support a diagnosis of IGM 100/2010 as an enantiornithine. Re-identification eliminates the implied homoplasy of this tri-laminate eggshell structure, and instead associates enantiornithine birds with eggshell microstructure composed of a mammillary, squamatic, and external zones. Posture of the embryo follows that of other theropods with fore- and hindlimbs folded parallel to the vertebral column and the elbow pointing caudally just dorsal to the knees. The size of the egg and embryo of IGM 100/2010 is similar to the two other Mongolian enantiornithine eggs. Well-ossified skeletons, as in this specimen, characterize all known enantiornithine embryos suggesting precocial hatchlings, comparing closely to late stage embryos of modern precocial birds that are both flight- and run-capable upon hatching. Extensive ossification in enantiornithine embryos may contribute to their relatively abundant representation in the fossil record. Neoceratopsian eggs remain unrecognized in the fossil record.
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Affiliation(s)
- David J. Varricchio
- Department of Earth Sciences, Montana State University, Bozeman, Montana, 59717, United States of America
- * E-mail:
| | - Amy M. Balanoff
- Department of Anatomical Sciences, Stony Brook University School of Medicine, Stony Brook, NY, 11794, United States of America
| | - Mark A. Norell
- Division of Paleontology, American Museum of Natural History, New York, NY, 10024, United States of America
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100
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Rensberger JM, Martínez RN. Bone cells in birds show exceptional surface area, a characteristic tracing back to saurischian dinosaurs of the late Triassic. PLoS One 2015; 10:e0119083. [PMID: 25830561 PMCID: PMC4382344 DOI: 10.1371/journal.pone.0119083] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2014] [Accepted: 01/27/2015] [Indexed: 11/23/2022] Open
Abstract
Background Dinosaurs are unique among terrestrial tetrapods in their body sizes, which range from less than 3 gm in hummingbirds to 70,000 kg or more in sauropods. Studies of the microstructure of bone tissue have indicated that large dinosaurs, once believed to be slow growing, attained maturity at rates comparable to or greater than those of large mammals. A number of structural criteria in bone tissue have been used to assess differences in rates of osteogenesis in extinct taxa, including counts of lines of arrested growth and the density of vascular canals. Methodology/Principal Findings Here, we examine the density of the cytoplasmic surface of bone-producing cells, a feature which may set an upper limit to the rate of osteogenesis. Osteocyte lacunae and canaliculi, the cavities in bone containing osteocytes and their extensions, were measured in thin-sections of primary (woven and parallel fibered) bone in a diversity of tetrapods. The results indicate that bone cell surfaces are more densely organized in the Saurischia (extant birds, extinct Mesozoic Theropoda and Sauropodomorpha) than in other tetrapods, a result of denser branching of the cell extensions. The highest postnatal growth rates among extant tetrapods occur in modern birds, the only surviving saurischians, and the finding of exceptional cytoplasmic surface area of the cells that produce bone in this group suggests a relationship with bone growth rate. In support of this relationship is finding the lowest cell surface density among the saurischians examined in Dinornis, a member of a group of ratites that evolved in New Zealand in isolation from mammalian predators and show other evidence of lowered maturation rates.
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Affiliation(s)
- John M. Rensberger
- Department of Earth and Space Sciences, University of Washington, Seattle, Washington, United States of America
- * E-mail:
| | - Ricardo N. Martínez
- Museo de Ciencias Naturales, Universidad Nacional de San Juan, San Juan, Argentina
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