1
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Bhat MS, Cullen TM. Growth and life history of freshwater chelydrid turtles (Testudines: Cryptodira): A bone histological approach. J Anat 2024. [PMID: 39169639 DOI: 10.1111/joa.14130] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2024] [Revised: 07/25/2024] [Accepted: 08/07/2024] [Indexed: 08/23/2024] Open
Abstract
The current study examines the growth pattern and lifestyle habits of the freshwater snapping turtles Chelydra and Macrochelys based on limb bone histology. Femora, humeri, and tibiae of 25 individuals selected from a range of ontogenetic stages were assessed to determine inter-element and intraskeletal histological variation. Osteohistological assessment of multiple elements is consistent with overall moderate growth rates as revealed by the dominance of parallel-fibered bone. However, the growth was cyclical as shown by deposition of multiple lines of arrested growths in the compacta. It appears that the bone tissue of C. serpentina is more variable through ontogeny with intermittent higher growth rates. M. temminckii appears to grow more slowly than C. serpentina possessing compact and thick cortices in accordance with their larger size. Overall, vascularization decreases through ontogeny with humeri and femora being well-vascularized in both species. Contrarily, epipodials are poorly vascularized, though simple longitudinal and radial canals are present, suggesting differences in growth patterns when compared with associated diaphyseal sections. The tibiae were found to be the least remodeled of the limb bones and therefore better suited for skeletochronology for snapping turtles. Intra-elementally, femora and humeri preserved higher cortical vascularity ventrally, suggestive of faster relative growth. We hypothesize that the differential growth pattern in limb bones of snapping turtles may relate to differential functional constraints, where forelimbs are operational in swimming while the hindlimbs provide stability.
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Affiliation(s)
- Mohd Shafi Bhat
- Department of Geosciences, Auburn University, Auburn, Alabama, USA
| | - Thomas M Cullen
- Department of Geosciences, Auburn University, Auburn, Alabama, USA
- Auburn University Museum of Natural History, Auburn, Alabama, USA
- Department of Earth Sciences, Carleton University, Ottawa, Ontario, Canada
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Habib MB, Hone DWE. Intraspecific variation in the pterosaur Rhamphorhynchus muensteri-implications for flight and socio-sexual signaling. PeerJ 2024; 12:e17524. [PMID: 39035160 PMCID: PMC11260407 DOI: 10.7717/peerj.17524] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2023] [Accepted: 05/16/2024] [Indexed: 07/23/2024] Open
Abstract
Pterosaurs were the first powered flying vertebrates, with a fossil record that stretches back to about 230 million years before present. Most species are only known from one to three specimens, which are most often fragmentary. However, Rhamphorhynchus muensteri is known from numerous excellent specimens, including multiple specimens with soft tissue preservation. As such, Rhamphorhynchus muensteri is one of the only pterosaurs amenable to analysis for intraspecific variation. It has been previously predicted that elements directly involved in the flight apparatus, such as those of the forelimb, will be more highly constrained in their proportions than other parts of the skeleton. We investigated the degree of variation seen in elements and body parts of Rhamphorhynchus, which represents the best model system among pterosaurs for testing these expectations of intraspecific variation. We recover evidence for high levels of constraint throughout the appendicular and axial elements (head, neck, torso, tail, forelimbs, hindlimbs), suggesting that all were important for flight. We further find that tail variation increases among the largest specimens, suggesting reduced constraint and/or stronger sexual selection on the tail in more mature individuals.
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Affiliation(s)
- Michael B. Habib
- Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, California, United States
- Medicine, University of California, Los Angeles, Los Angeles, CA, United States
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Yang Z, Jiang B, Benton MJ, Xu X, McNamara ME, Hone DWE. Allometric wing growth links parental care to pterosaur giantism. Proc Biol Sci 2023; 290:20231102. [PMID: 37464754 DOI: 10.1098/rspb.2023.1102] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Accepted: 06/28/2023] [Indexed: 07/20/2023] Open
Abstract
Pterosaurs evolved a broad range of body sizes, from small-bodied early forms with wingspans of mostly 1-2 m to the last-surviving giants with sizes of small airplanes. Since all pterosaurs began life as small hatchlings, giant forms must have attained large adult sizes through new growth strategies, which remain largely unknown. Here we assess wing ontogeny and performance in the giant Pteranodon and the smaller-bodied anurognathids Rhamphorhynchus, Pterodactylus and Sinopterus. We show that most smaller-bodied pterosaurs shared negative allometry or isometry in the proximal elements of the fore- and hindlimbs, which were critical elements for powering both flight and terrestrial locomotion, whereas these show positive allometry in Pteranodon. Such divergent growth allometry typically signals different strategies in the precocial-altricial spectrum, suggesting more altricial development in Pteranodon. Using a biophysical model of powered and gliding flight, we test and reject the hypothesis that an aerodynamically superior wing planform could have enabled Pteranodon to attain its larger body size. We therefore propose that a shift from a plesiomorphic precocial state towards a derived state of enhanced parental care may have relaxed the constraints of small body sizes and allowed the evolution of derived flight anatomies critical for the flying giants.
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Affiliation(s)
- Zixiao Yang
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork T23 TK30, Ireland
- Environmental Research Institute, Ellen Hutchins Building, Lee Road, Cork T23 XE10, Ireland
| | - Baoyu Jiang
- Center for Research and Education on Biological Evolution and Environments, School of Earth Sciences and Engineering, Nanjing University, Nanjing 210023, People's Republic of China
| | - Michael J Benton
- School of Earth Sciences, University of Bristol, Life Sciences Building, Tyndall Avenue, Bristol BS8 1TQ, UK
| | - Xing Xu
- Center for Vertebrate Evolutionary Biology, Yunnan University, Kunming 650031, People's Republic of China
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing 100044, People's Republic of China
| | - Maria E McNamara
- School of Biological, Earth and Environmental Sciences, University College Cork, Cork T23 TK30, Ireland
- Environmental Research Institute, Ellen Hutchins Building, Lee Road, Cork T23 XE10, Ireland
| | - David W E Hone
- School of Biological and Behavioural Sciences, Queen Mary University of London, Mile End Road, London E1 4NS, UK
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Wu Q, Chen H, Li Z, Jiang S, Wang X, Zhou Z. The morphology and histology of the pectoral girdle of Hamipterus (Pterosauria), from the Early Cretaceous of Northwest China. Anat Rec (Hoboken) 2023. [PMID: 36787121 DOI: 10.1002/ar.25167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2022] [Revised: 01/05/2023] [Accepted: 01/10/2023] [Indexed: 02/15/2023]
Abstract
As one of the mysteries volant vertebrates, pterosaurs were completely extinct in the K-Pg extinction event, which hampered our understanding of their flight. Recent studies on pterosaur flight usually use birds as analogies, since their shoulder girdle share many features. However, it was also proposed that these two groups may differ in some critical flight mechanisms, such as the primary muscles for the upstroke of the wings. Here, we describe and characterize the detail features of the pectoral girdle morphology and histology in Hamipterus from the Early Cretaceous of Northwest China for the first time. Our research reveals that the scapula and coracoid of Hamipterus form a synostosis joint, representing a distinct pectoral girdle adaption during pterosaur flight evolution, different from that of birds. The residual of the articular cartilage of the glenoid fossa supports the potential for cartilage tissue preservation in this location. The morphology of the acrocoracoid process of Hamipterus indicates it may work as a pulley for M. supracoracoideus as the main power of flight upstroke resembles that of birds. But the saddle type of the shoulder joint of the pterosaur may limit the rotation of the humerus head, suggesting a particular mechanism to control the angle of attack unlike birds. The presence of both the similarity and differences between the flight apparatus of pterosaurs and birds are highlighted in our research, which may be related to the flight mechanism and forelimb functional adaption. The distinctive feature of the flight apparatus of pterosaur should be treated with caution in future research, to better understand the life of this unique extinct volant vertebrate.
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Affiliation(s)
- Qian Wu
- University of the Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
| | - He Chen
- School of Ecology, Sun Yat-sen University, Shenzhen, China
| | - Zhiheng Li
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
| | - Shunxing Jiang
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
| | - Xiaolin Wang
- University of the Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
| | - Zhonghe Zhou
- University of the Chinese Academy of Sciences, Beijing, China
- Key Laboratory of Vertebrate Evolution and Human Origins, Institute of Vertebrate Paleontology and Paleoanthropology, Chinese Academy of Sciences, Beijing, China
- CAS Center for Excellence in Life and Paleoenvironment, Beijing, China
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5
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Zhou CF, Yu D, Zhu Z, Andres B. A new wing skeleton of the Jehol tapejarid Sinopterus and its implications for ontogeny and paleoecology of the Tapejaridae. Sci Rep 2022; 12:10159. [PMID: 35715498 PMCID: PMC9205892 DOI: 10.1038/s41598-022-14111-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/12/2022] [Accepted: 06/01/2022] [Indexed: 11/13/2022] Open
Abstract
The tapejarid pterosaurs flourished in the Jehol Biota with an abundance of immature individuals and a rarity of individuals at skeletal maturity. Most of these individuals plot well on an ontogenetic series based on the proportions of limb elements, but this has lacked histological evidence until now. Here, a new wing skeleton of Sinopterus was thin-sectioned to provide the first histological data about the ontogeny of the Jehol tapejarids. Histologically, the new specimen is an immature individual at a late juvenile stage prior to sexual maturity. It is grouped with medium-sized and medium-crested individuals, which are distinct from the small-sized and crestless individuals as well as the rare large-sized and large-crested individuals at skeletal maturity, supporting the presence of the premaxillary crest as an ontogenetic feature in the Jehol tapejarids. Furthermore, this histology indicates that the largest skeletally immature individuals might have reached the sexual maturity. Enigmatically, there is a size gap between sexual and skeletal maturity, which is at about 79% of the large size, implying a ontogenetic strategy comparable with Pteranodon and possibly with the Brazilian tapejarid Caiuajara. This size gap is consistent with lack of the larger sexually mature individuals in the Jehol Biota, which is hypothesized to be a migratory habitat for the Jehol tapejarids.
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Affiliation(s)
- Chang-Fu Zhou
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, Shandong Province, China.
| | - Dongxiang Yu
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, Shandong Province, China
| | - Ziheng Zhu
- College of Earth Science and Engineering, Shandong University of Science and Technology, Qingdao, Shandong Province, China
| | - Brian Andres
- Department of Health, University College Birmingham, Birmingham, UK
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Prondvai E, Kocsis AT, Abourachid A, Adriaens D, Godefroit P, Hu DY, Butler RJ. Radial porosity profiles: a new bone histological method for comparative developmental analysis of diametric limb bone growth. ROYAL SOCIETY OPEN SCIENCE 2022; 9:211893. [PMID: 35582660 PMCID: PMC9091851 DOI: 10.1098/rsos.211893] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 12/01/2021] [Accepted: 04/13/2022] [Indexed: 06/15/2023]
Abstract
In fossil tetrapods, limb bone histology is considered the most reliable tool not only for inferring skeletal maturity-a crucial assessment in palaeobiological and evolutionary studies-but also for evaluating the growth dynamics within the ontogenetic window represented by the primary bone cortex. Due to its complex relationship with bone growth and functional maturation, primary cortical vascularity is an indispensable osteohistological character for reconstructing growth dynamics, especially in the context of various developmental strategies along the precocial-altricial spectrum. Using this concept as our working hypothesis, we developed a new quantitative osteohistological parameter, radial porosity profile (RPP), that captures relative cortical porosity changes in limb bones as trajectories. We built a proof-of-concept RPP dataset on extant birds, then added fossil paravian dinosaurs and performed a set of trajectory-grouping analyses to identify potential RPP categories and evaluate them in the context of our ontogeny-developmental strategy working hypothesis. We found that RPPs, indeed, reflect important developmental features within and across elements, specimens and taxa, supporting their analytical power. Our RPPs also revealed unexpected potential osteohistological correlates of growth and functional development of limb bones. The diverse potential applications of RPPs open up new research directions in the evolution of locomotor ontogeny.
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Affiliation(s)
- Edina Prondvai
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
- MTA-MTM-ELTE Research Group for Paleontology, Budapest, Hungary
| | - Adam T. Kocsis
- Department of Palaeobiology, Friedrich-Alexander-University of Erlangen-Nürnberg, Erlangen, Germany
| | - Anick Abourachid
- Département Adaptations du Vivant, UMR 7179 Muséum National d'Histoire Naturelle – CNRS, Paris, France
| | - Dominique Adriaens
- Department of Biology, Evolutionary Morphology of Vertebrates, Ghent University, Ghent, Belgium
| | - Pascal Godefroit
- Directorate Earth and History of Life, Royal Belgian Institute of Natural Sciences, Brussels, Belgium
| | - Dong-Yu Hu
- Key Laboratory for Evolution of Past Life in Northeast Asia, Ministry of Land and Resources, Paleontological Institute of Shenyang Normal University, Shenyang, People's Republic of China
- Paleontological Museum of Liaoning, Shenyang, People's Republic of China
| | - Richard J. Butler
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, UK
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Jagielska N, O’Sullivan M, Funston GF, Butler IB, Challands TJ, Clark ND, Fraser NC, Penny A, Ross DA, Wilkinson M, Brusatte SL. A skeleton from the Middle Jurassic of Scotland illuminates an earlier origin of large pterosaurs. Curr Biol 2022; 32:1446-1453.e4. [DOI: 10.1016/j.cub.2022.01.073] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/10/2021] [Accepted: 01/25/2022] [Indexed: 11/30/2022]
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Naish D, Witton MP, Martin-Silverstone E. Powered flight in hatchling pterosaurs: evidence from wing form and bone strength. Sci Rep 2021; 11:13130. [PMID: 34294737 PMCID: PMC8298463 DOI: 10.1038/s41598-021-92499-z] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2019] [Accepted: 06/10/2021] [Indexed: 11/09/2022] Open
Abstract
Competing views exist on the behaviour and lifestyle of pterosaurs during the earliest phases of life. A 'flap-early' model proposes that hatchlings were capable of independent life and flapping flight, a 'fly-late' model posits that juveniles were not flight capable until 50% of adult size, and a 'glide-early' model requires that young juveniles were flight-capable but only able to glide. We test these models by quantifying the flight abilities of very young juvenile pterosaurs via analysis of wing bone strength, wing loading, wingspan and wing aspect ratios, primarily using data from embryonic and hatchling specimens of Pterodaustro guinazui and Sinopterus dongi. We argue that a young Sinopterus specimen has been mischaracterised as a distinct taxon. The humeri of pterosaur juveniles are similar in bending strength to those of adults and able to withstand launch and flight; wing size and wing aspect ratios of young juveniles are also in keeping with powered flight. We therefore reject the 'fly-late' and 'glide-early' models. We further show that young juveniles were excellent gliders, albeit not reliant on specialist gliding. The wing forms of very young juveniles differ significantly from larger individuals, meaning that variation in speed, manoeuvrability, take-off angle and so on was present across a species as it matured. Juveniles appear to have been adapted for flight in cluttered environments, in contrast to larger, older individuals. We propose on the basis of these conclusions that pterosaur species occupied distinct niches across ontogeny.
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Affiliation(s)
- Darren Naish
- School of Biological Sciences, Faculty of Environment & Life Sciences, University of Southampton, University Road, Southampton, SO17 1BJ, UK.
| | - Mark P Witton
- School of the Environment, Geography and Geosciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth, PO1 3QL, UK
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Griffin CT, Stocker MR, Colleary C, Stefanic CM, Lessner EJ, Riegler M, Formoso K, Koeller K, Nesbitt SJ. Assessing ontogenetic maturity in extinct saurian reptiles. Biol Rev Camb Philos Soc 2020; 96:470-525. [PMID: 33289322 DOI: 10.1111/brv.12666] [Citation(s) in RCA: 41] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Revised: 10/09/2020] [Accepted: 10/28/2020] [Indexed: 01/06/2023]
Abstract
Morphology forms the most fundamental level of data in vertebrate palaeontology because it is through interpretations of morphology that taxa are identified, creating the basis for broad evolutionary and palaeobiological hypotheses. Assessing maturity is one of the most basic aspects of morphological interpretation and provides the means to study the evolution of ontogenetic changes, population structure and palaeoecology, life-history strategies, and heterochrony along evolutionary lineages that would otherwise be lost to time. Saurian reptiles (the least-inclusive clade containing Lepidosauria and Archosauria) have remained an incredibly diverse, numerous, and disparate clade through their ~260-million-year history. Because of the great disparity in this group, assessing maturity of saurian reptiles is difficult, fraught with methodological and terminological ambiguity. We compiled a novel database of literature, assembling >900 individual instances of saurian maturity assessment, to examine critically how saurian maturity has been diagnosed. We review the often inexact and inconsistent terminology used in saurian maturity assessment (e.g. 'juvenile', 'mature') and provide routes for better clarity and cross-study coherence. We describe the various methods that have been used to assess maturity in every major saurian group, integrating data from both extant and extinct taxa to give a full account of the current state of the field and providing method-specific pitfalls, best practices, and fruitful directions for future research. We recommend that a new standard subsection, 'Ontogenetic Assessment', be added to the Systematic Palaeontology portions of descriptive studies to provide explicit ontogenetic diagnoses with clear criteria. Because the utility of different ontogenetic criteria is highly subclade dependent among saurians, even for widely used methods (e.g. neurocentral suture fusion), we recommend that phylogenetic context, preferably in the form of a phylogenetic bracket, be used to justify the use of a maturity assessment method. Different methods should be used in conjunction as independent lines of evidence when assessing maturity, instead of an ontogenetic diagnosis resting entirely on a single criterion, which is common in the literature. Critically, there is a need for data from extant taxa with well-represented growth series to be integrated with the fossil record to ground maturity assessments of extinct taxa in well-constrained, empirically tested methods.
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Affiliation(s)
- Christopher T Griffin
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
| | - Michelle R Stocker
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
| | - Caitlin Colleary
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Vertebrate Paleontology, Cleveland Museum of Natural History, 1 Wade Oval Drive, Cleveland, OH, 44106, U.S.A
| | - Candice M Stefanic
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Anatomical Sciences, Stony Brook University, 100 Nicolls Road, Stony Brook, NY, 11794, U.S.A
| | - Emily J Lessner
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Pathology and Anatomical Sciences, University of Missouri, 1 Hospital Drive, Columbia, MO, 65212, U.S.A
| | - Mitchell Riegler
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Geological Sciences, University of Florida, 241 Williamson Hall, Gainesville, FL, 32611, U.S.A
| | - Kiersten Formoso
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Earth Sciences, University of Southern California, 3651 Trousdale Pkwy, Los Angeles, CA, 90089, U.S.A
- Dinosaur Institute, Natural History Museum of Los Angeles County, 900 W Exposition Boulevard, Los Angeles, CA, 90007, U.S.A
| | - Krista Koeller
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
- Department of Biology, University of Florida, 220 Bartram Hall, Gainesville, FL, 32611, U.S.A
| | - Sterling J Nesbitt
- Department of Geosciences, Virginia Tech, 926 West Campus Drive, Blacksburg, VA, 24061, U.S.A
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Bestwick J, Unwin DM, Butler RJ, Purnell MA. Dietary diversity and evolution of the earliest flying vertebrates revealed by dental microwear texture analysis. Nat Commun 2020; 11:5293. [PMID: 33116130 PMCID: PMC7595196 DOI: 10.1038/s41467-020-19022-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2020] [Accepted: 09/25/2020] [Indexed: 11/26/2022] Open
Abstract
Pterosaurs, the first vertebrates to evolve active flight, lived between 210 and 66 million years ago. They were important components of Mesozoic ecosystems, and reconstructing pterosaur diets is vital for understanding their origins, their roles within Mesozoic food webs and the impact of other flying vertebrates (i.e. birds) on their evolution. However, pterosaur dietary hypotheses are poorly constrained as most rely on morphological-functional analogies. Here we constrain the diets of 17 pterosaur genera by applying dental microwear texture analysis to the three-dimensional sub-micrometre scale tooth textures that formed during food consumption. We reveal broad patterns of dietary diversity (e.g. Dimorphodon as a vertebrate consumer; Austriadactylus as a consumer of 'hard' invertebrates) and direct evidence of sympatric niche partitioning (Rhamphorhynchus as a piscivore; Pterodactylus as a generalist invertebrate consumer). We propose that the ancestral pterosaur diet was dominated by invertebrates and later pterosaurs evolved into piscivores and carnivores, shifts that might reflect ecological displacements due to pterosaur-bird competition.
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Affiliation(s)
- Jordan Bestwick
- Centre for Palaeobiology Research, School of Geography, Geology and the Environment, University of Leicester, Leicester, LE1 7RH, UK.
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK.
| | - David M Unwin
- Centre for Palaeobiology Research, School of Museum Studies, University of Leicester, Leicester, LE1 7RF, UK
| | - Richard J Butler
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, B15 2TT, UK
| | - Mark A Purnell
- Centre for Palaeobiology Research, School of Geography, Geology and the Environment, University of Leicester, Leicester, LE1 7RH, UK.
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Kellner AWA, Rodrigues T, Costa FR, Weinschütz LC, Figueiredo RG, Souza GADE, Brum AS, Eleutério LHS, Mueller CW, Sayão JM. Pterodactyloid pterosaur bones from Cretaceous deposits of the Antarctic Peninsula. AN ACAD BRAS CIENC 2019; 91:e20191300. [PMID: 31800676 DOI: 10.1590/0001-3765201920191300] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2019] [Accepted: 11/06/2019] [Indexed: 11/21/2022] Open
Abstract
Fossil vertebrates from Antarctica are considerably rare, hampering our understanding of the evolutionary history of the biota from that continent. For several austral summers, the PALEOANTAR project has been carrying out fieldwork in the Antarctic Peninsula in search for fossils, particularly Cretaceous vertebrates. Among the specimens recovered so far are two bones referable to Pterosauria, more specifically to the Pterodacyloidea, the first volant reptiles from Antarctica to be fully described. MN 7800-V (part and counterpart) was recovered from a moraine at the Abernathy Flats (Santa Marta Formation, Lachman Crags Member, Santonian-Campanian) on James Ross Island. It is interpreted as the distal articulation of a first phalanx of the wing finger, representing an animal with an estimated wingspan between 3 and 4 m. The second specimen (MN 7801-V) comes from Vega Island (Snow Hill Island Formation, Maastrichtian) and is identified as a wing metacarpal IV of an animal with an estimated wingspan from 4 to 5 m. These occurrences show that pterodactyloids inhabited the Antarctic Peninsula at least during the Upper Cretaceous and demonstrate that large pterosaurs were widespread through all parts of the planet during that period.
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Affiliation(s)
- Alexander W A Kellner
- Laboratório de Paleontologia, Departamento de Ciências Biológicas, Centro de Ciências Humanas e Naturais, Universidade Federal do Espírito Santo, Avenida Fernando Ferrari, 514, 29075-910 Vitória, ES, Brazil
| | - Taissa Rodrigues
- Laboratório de Paleontologia, Departamento de Ciências Biológicas, Centro de Ciências Humanas e Naturais, Universidade Federal do Espírito Santo, Avenida Fernando Ferrari, 514, 29075-910 Vitória, ES, Brazil
| | - Fabiana R Costa
- Laboratório de Paleontologia de Vertebrados e Comportamento Animal/LAPC, Centro de Ciências Naturais e Humanas/CCNH, Universidade Federal do ABC, Rua São Paulo, s/n, Jardim Antares, 09606-045 São Bernardo do Campo, SP, Brazil
| | - Luiz C Weinschütz
- CENPALEO - Centro Paleontológico da Universidade do Contestado, Universidade do Contestado, 89306-076 Mafra, SC, Brazil
| | - Rodrigo G Figueiredo
- Departamento de Biologia, Universidade Federal do Espírito Santo, Alto Universitário, s/n, Guararema, 29500-000 Alegre, ES, Brazil
| | - Geovane A DE Souza
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
| | - Arthur S Brum
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
| | - Lúcia H S Eleutério
- Laboratório de Paleobiologia e Microestruturas, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Rua do Alto Reservatório, s/n, Bela Vista, 55608-680 Vitória do Santo Antão, PE, Brazil.,Programa de Pós-Graduação em Geociências, Universidade Federal de Pernambuco/UFPE, Centro de Tecnologia e Geociências, Av. da Arquitetura, s/n, Cidade Universitária, 50740-550 Recife, PE, Brazil
| | - Carsten W Mueller
- Technical University of Munich, Chair of Soil Science, Emil-Ramann-Strasse 2, 85354, Freising-Weihenstephan, Germany
| | - Juliana M Sayão
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil.,Laboratório de Paleobiologia e Microestruturas, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Rua do Alto Reservatório, s/n, Bela Vista, 55608-680 Vitória do Santo Antão, PE, Brazil
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12
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Kellner AWA, Weinschütz LC, Holgado B, Bantim RAM, Sayão JM. A new toothless pterosaur (Pterodactyloidea) from Southern Brazil with insights into the paleoecology of a Cretaceous desert. AN ACAD BRAS CIENC 2019; 91:e20190768. [PMID: 31432888 DOI: 10.1590/0001-3765201920190768] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Accepted: 08/06/2019] [Indexed: 11/22/2022] Open
Abstract
The first pterosaur bone bed from Brazil was reported in 2014 at the outskirts of the town Cruzeiro do Oeste, Paraná State, in the Southern region of the country. Here named 'cemitério dos pterossauros' site, these outcrops were referred to the Goio-Erê Formation (Turonian-Campanian) of the Caiuá Group (Bauru Basin) and revealed the presence of hundreds of isolated or partially articulated elements of the tapejarine pterosaur Caiuajara and fewer amounts of a theropod dinosaur. Here we present a new tapejaromorph flying reptile from this site, Keresdrakon vilsoni gen. et sp. nov., which shows a unique blunt ridge on the dorsal surface of the posterior end of the dentary. Morphological and osteohistological features indicate that all recovered individuals represent late juveniles or sub-adults. This site shows the first direct evidence of sympatry in Pterosauria. The two distinct flying reptiles coexisted with a theropod dinosaur, providing a rare glimpse of a paleobiological community from a Cretaceous desert.
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Affiliation(s)
- Alexander W A Kellner
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil
| | - Luiz C Weinschütz
- CENPALEO - Centro Paleontológico da Universidade do Contestado, Universidade do Contestado, Jardim do Moinho, 89306-076 Mafra, SC, Brazil
| | - Borja Holgado
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil.,Institut Català de Paleontologia 'Miquel Crusafont' (ICP), C/ de les Columnes, Universitat Autònoma de Barcelona, E-08193 Cerdanyola del Vallès, Barcelona, Catalonia, Spain
| | - Renan A M Bantim
- Laboratório de Paleontologia, Universidade Regional do Cariri (URCA), Rua Coronel Antônio Luiz, 1161, 63195-000 Crato, CE, Brazil
| | - Juliana M Sayão
- Laboratory of Systematics and Taphonomy of Fossil Vertebrates, Departamento de Geologia e Paleontologia, Museu Nacional/Universidade Federal do Rio de Janeiro, Quinta da Boa Vista, s/n, São Cristóvão, 20940-040 Rio de Janeiro, RJ, Brazil.,Laboratório de Paleobiologia e Microestruturas, Centro Acadêmico de Vitória, Universidade Federal de Pernambuco, Rua do Alto Reservatório, s/n, Bela Vista, 55608-680 Vitória do Santo Antão, PE, Brazil
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13
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Unwin DM, Deeming DC. Prenatal development in pterosaurs and its implications for their postnatal locomotory ability. Proc Biol Sci 2019; 286:20190409. [PMID: 31185866 DOI: 10.1098/rspb.2019.0409] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent fossil finds in China and Argentina have provided startling new insights into the reproductive biology and embryology of pterosaurs, Mesozoic flying reptiles. Nineteen embryos distributed among four species representing three distinct clades have been described and all are assumed to be at, or near, term. We show here how the application of four contrasting quantitative approaches allows a more precise identification of the developmental status of embryos revealing, for the first time to our knowledge, the presence of middle and late developmental stages as well as individuals that were at term. We also identify a predicted relationship between egg size and shape and the developmental stage of embryos contained within. Small elongate eggs contain embryos at an earlier stage of development than larger rounder eggs which contain more fully developed embryos. Changes in egg shape and size probably reflect the uptake of water, consistent with a pliable shell reported for several pterosaurs. Early ossification of the vertebral column, limb girdles and principal limb bones involved some heterochronic shifts in appearance times, most notably of manus digit IV, and facilitated full development of the flight apparatus prior to hatching. This is consistent with a super-precocial flight ability and, while not excluding the possibility of parental care in pterosaurs, suggests that it was not an absolute requirement.
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Affiliation(s)
- David Michael Unwin
- 1 School of Museum Studies, University of Leicester , 19 University Road, Leicester LE1 7RF , UK
| | - D Charles Deeming
- 2 School of Life Sciences, University of Lincoln , Joseph Banks Laboratories, Green Lane, Lincoln LN6 7DL , UK
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14
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Griffin CT, Bano LS, Turner AH, Smith ND, Irmis RB, Nesbitt SJ. Integrating gross morphology and bone histology to assess skeletal maturity in early dinosauromorphs: new insights from Dromomeron (Archosauria: Dinosauromorpha). PeerJ 2019; 7:e6331. [PMID: 30775169 PMCID: PMC6375289 DOI: 10.7717/peerj.6331] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2018] [Accepted: 12/20/2018] [Indexed: 12/16/2022] Open
Abstract
Understanding growth patterns is central to properly interpreting paleobiological signals in tetrapods, but assessing skeletal maturity in some extinct clades may be difficult when growth patterns are poorly constrained by a lack of ontogenetic series. To overcome this difficulty in assessing the maturity of extinct archosaurian reptiles—crocodylians, birds and their extinct relatives—many studies employ bone histology to observe indicators of the developmental stage reached by a given individual. However, the relationship between gross morphological and histological indicators of maturity has not been examined in most archosaurian groups. In this study, we examined the gross morphology of a hypothesized growth series of Dromomeron romeri femora (96.6–144.4 mm long), the first series of a non-dinosauriform dinosauromorph available for such a study. We also histologically sampled several individuals in this growth series. Previous studies reported that D. romeri lacks well-developed rugose muscle scars that appear during ontogeny in closely related dinosauromorph taxa, so integrating gross morphology and histological signal is needed to determine reliable maturity indicators for early bird-line archosaurs. We found that, although there are small, linear scars indicating muscle attachment sites across the femur, the only rugose muscle scar that appears during ontogeny is the attachment of the M. caudofemoralis longus, and only in the largest-sampled individual. This individual is also the only femur with histological indicators that asymptotic size had been reached, although smaller individuals possess some signal of decreasing growth rates (e.g., decreasing vascular density). The overall femoral bone histology of D. romeri is similar to that of other early bird-line archosaurs (e.g., woven-bone tissue, moderately to well-vascularized, longitudinal vascular canals). All these data indicate that the lack of well-developed femoral scars is autapomorphic for this species, not simply an indication of skeletal immaturity. We found no evidence of the high intraspecific variation present in early dinosaurs and other dinosauriforms, but a limited sample size of other early bird-line archosaur growth series make this tentative. The evolutionary history and phylogenetic signal of gross morphological features must be considered when assessing maturity in extinct archosaurs and their close relatives, and in some groups corroboration with bone histology or with better-known morphological characters is necessary.
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Affiliation(s)
| | - Lauren S Bano
- Department of Biology, Virginia Tech, Blacksburg, VA, USA
| | - Alan H Turner
- Department of Anatomical Sciences, Stony Brook University, Stony Brook, NY, USA
| | - Nathan D Smith
- The Dinosaur Institute, Natural History Museum of Los Angeles County, Los Angeles, CA, USA
| | - Randall B Irmis
- Natural History Museum of Utah, University of Utah, Salt Lake City, UT, USA.,Department of Geology and Geophysics, University of Utah, Salt Lake City, UT, USA
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15
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Bestwick J, Unwin DM, Butler RJ, Henderson DM, Purnell MA. Pterosaur dietary hypotheses: a review of ideas and approaches. Biol Rev Camb Philos Soc 2018; 93:2021-2048. [PMID: 29877021 PMCID: PMC6849529 DOI: 10.1111/brv.12431] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2017] [Revised: 05/03/2018] [Accepted: 05/11/2018] [Indexed: 11/29/2022]
Abstract
Pterosaurs are an extinct group of Mesozoic flying reptiles, whose fossil record extends from approximately 210 to 66 million years ago. They were integral components of continental and marginal marine ecosystems, yet their diets remain poorly constrained. Numerous dietary hypotheses have been proposed for different pterosaur groups, including insectivory, piscivory, carnivory, durophagy, herbivory/frugivory, filter-feeding and generalism. These hypotheses, and subsequent interpretations of pterosaur diet, are supported by qualitative (content fossils, associations, ichnology, comparative anatomy) and/or quantitative (functional morphology, stable isotope analysis) evidence. Pterosaur dietary interpretations are scattered throughout the literature with little attention paid to the supporting evidence. Reaching a robustly supported consensus on pterosaur diets is important for understanding their dietary evolution, and their roles in Mesozoic ecosystems. A comprehensive examination of the pterosaur literature identified 314 dietary interpretations (dietary statement plus supporting evidence) from 126 published studies. Multiple alternative diets have been hypothesised for most principal taxonomic pterosaur groups. Some groups exhibit a high degree of consensus, supported by multiple lines of evidence, while others exhibit less consensus. Qualitative evidence supports 87.3% of dietary interpretations, with comparative anatomy most common (62.1% of total). More speciose groups of pterosaur tend to have a greater range of hypothesised diets. Consideration of dietary interpretations within alternative phylogenetic contexts reveals high levels of consensus between equivalent monofenestratan groups, and lower levels of consensus between equivalent non-monofenestratan groups. Evaluating the possible non-biological controls on apparent patterns of dietary diversity reveals that numbers of dietary interpretations through time exhibit no correlation with patterns of publication (number of peer-reviewed publications through time). 73.8% of dietary interpretations were published in the 21st century. Overall, consensus interpretations of pterosaur diets are better accounted for by non-biological signals, such as the impact of the respective quality of the fossil record of different pterosaur groups on research levels. That many interpretations are based on qualitative, often untestable lines of evidence adds significant noise to the data. More experiment-led pterosaur dietary research, with greater consideration of pterosaurs as organisms with independent evolutionary histories, will lead to more robust conclusions drawn from repeatable results. This will allow greater understanding of pterosaur dietary diversity, disparity and evolution and facilitate reconstructions of Mesozoic ecosystems.
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Affiliation(s)
- Jordan Bestwick
- School of Geography, Geology and the EnvironmentUniversity of LeicesterLeicesterLE1 7RHU.K.
| | - David M. Unwin
- School of Museum StudiesUniversity of LeicesterLeicesterLE1 7RFU.K.
| | - Richard J. Butler
- School of Geography, Earth and Environmental SciencesUniversity of BirminghamBirminghamB15 2TTU.K.
| | - Donald M. Henderson
- Royal Tyrrell Museum of Palaeontology, P.O. Box 7500DrumhellerAlberta, T0J 0Y0Canada
| | - Mark A. Purnell
- School of Geography, Geology and the EnvironmentUniversity of LeicesterLeicesterLE1 7RHU.K.
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16
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Legendre LJ, Botha-Brink J. Digging the compromise: investigating the link between limb bone histology and fossoriality in the aardvark ( Orycteropus afer). PeerJ 2018; 6:e5216. [PMID: 30018860 PMCID: PMC6045922 DOI: 10.7717/peerj.5216] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2018] [Accepted: 06/21/2018] [Indexed: 01/07/2023] Open
Abstract
Bone microstructure has long been known as a powerful tool to investigate lifestyle-related biomechanical constraints, and many studies have focused on identifying such constraints in the limb bones of aquatic or arboreal mammals in recent years. The limb bone microstructure of fossorial mammals, however, has not been extensively described. Furthermore, so far, studies on this subject have always focused on the bone histology of small burrowers, such as subterranean rodents or true moles. Physiological constraints associated with digging, however, are known to be strongly influenced by body size, and larger burrowers are likely to exhibit a histological profile more conspicuously influenced by fossorial activity. Here, we describe for the first time the limb bone histology of the aardvark (Orycteropus afer), the largest extant burrowing mammal. The general pattern is very similar for all six sampled limb bones (i.e., humerus, radius, ulna, femur, tibia, and fibula). Most of the cortex at midshaft is comprised of compacted coarse cancellous bone (CCCB), an endosteal tissue formed in the metaphyses through the compaction of bony trabeculae. Conversely, the periosteal bone is highly resorbed in all sections, and is reduced to a thin outer layer, suggesting a pattern of strong cortical drift. This pattern contrasts with that of most large mammals, in which cortical bone is of mostly periosteal origin, and CCCB, being a very compliant bone tissue type, is usually resorbed or remodeled during ontogeny. The link between histology and muscle attachment sites, as well as the influence of the semi-arid environment and ant-eating habits of the aardvark on its bone microstructure, are discussed. We hypothesize that the unusual histological profile of the aardvark is likely the outcome of physiological constraints due to both extensive digging behavior and strong metabolic restrictions. Adaptations to fossoriality are thus the result of a physiological compromise between limited food availability, an environment with high temperature variability, and the need for biomechanical resistance during digging. These results highlight the difficulties of deciphering all factors potentially involved in bone formation in fossorial mammals. Even though the formation and maintaining of CCCB through ontogeny in the aardvark cannot be unambiguously linked with its fossorial habits, a high amount of CCCB has been observed in the limb bones of other large burrowing mammals. The inclusion of such large burrowers in future histological studies is thus likely to improve our understanding of the functional link between bone growth and fossorial lifestyle in an evolutionary context.
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Affiliation(s)
- Lucas J Legendre
- Karoo Palaeontology Department, National Museum, Bloemfontein, South Africa
| | - Jennifer Botha-Brink
- Karoo Palaeontology Department, National Museum, Bloemfontein, South Africa.,Department of Zoology and Entomology, University of the Free State, Bloemfontein, South Africa
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17
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Chan NR. Morphospaces of functionally analogous traits show ecological separation between birds and pterosaurs. Proc Biol Sci 2017; 284:rspb.2017.1556. [PMID: 29046377 DOI: 10.1098/rspb.2017.1556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/11/2017] [Accepted: 09/19/2017] [Indexed: 11/12/2022] Open
Abstract
Birds originated and radiated in the presence of another group of flying vertebrates, the pterosaurs. Opinion is divided as to whether birds competitively displaced pterosaurs from small-body size niches or whether the two groups coexisted with little competition. Previous studies of Mesozoic birds and pterosaurs compared measurements of homologous limb bones to test these hypotheses. However, these characters probably reflect differing ancestries rather than ecologies. Here, competition and ecological separation were tested for using multivariate analyses of functionally equivalent morphological characters. As well as using characters from the fore- and hindlimbs, these analyses also included measurements of the lower jaw. The results of this study indicate that pterosaurs had relatively longer jaws, shorter metatarsals and shorter brachial regions compared with birds of similar size. Contrary to the results of previous studies, the distal wing was not important for separating the two clades in morphospace owing to the inclusion of the primary feathers in this unit. The differences found here indicate ecological separation based on differences in size, locomotory features and feeding adaptations. Thus, instead of one group displacing the other, birds and pterosaurs appear to have adopted distinctive ecological strategies throughout their period of coexistence.
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Affiliation(s)
- Nicholas R Chan
- Department of Biological Sciences, Macquarie University, Sydney, New South Wales 2109, Australia
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18
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Myhrvold NP. Dinosaur Metabolism and the Allometry of Maximum Growth Rate. PLoS One 2016; 11:e0163205. [PMID: 27828977 PMCID: PMC5102473 DOI: 10.1371/journal.pone.0163205] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2015] [Accepted: 09/06/2016] [Indexed: 12/29/2022] Open
Abstract
The allometry of maximum somatic growth rate has been used in prior studies to classify the metabolic state of both extant vertebrates and dinosaurs. The most recent such studies are reviewed, and their data is reanalyzed. The results of allometric regressions on growth rate are shown to depend on the choice of independent variable; the typical choice used in prior studies introduces a geometric shear transformation that exaggerates the statistical power of the regressions. The maximum growth rates of extant groups are found to have a great deal of overlap, including between groups with endothermic and ectothermic metabolism. Dinosaur growth rates show similar overlap, matching the rates found for mammals, reptiles and fish. The allometric scaling of growth rate with mass is found to have curvature (on a log-log scale) for many groups, contradicting the prevailing view that growth rate allometry follows a simple power law. Reanalysis shows that no correlation between growth rate and basal metabolic rate (BMR) has been demonstrated. These findings drive a conclusion that growth rate allometry studies to date cannot be used to determine dinosaur metabolism as has been previously argued.
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Affiliation(s)
- Nathan P. Myhrvold
- Intellectual Ventures, Bellevue, Washington, United States of America
- * E-mail:
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19
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Martin-Silverstone E, Witton MP, Arbour VM, Currie PJ. A small azhdarchoid pterosaur from the latest Cretaceous, the age of flying giants. ROYAL SOCIETY OPEN SCIENCE 2016; 3:160333. [PMID: 27853614 PMCID: PMC5108964 DOI: 10.1098/rsos.160333] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/12/2016] [Accepted: 07/20/2016] [Indexed: 06/01/2023]
Abstract
Pterosaur fossils from the Campanian-Maastrichtian of North America have been reported from the continental interior, but few have been described from the west coast. The first pterosaur from the Campanian Northumberland Formation (Nanaimo Group) of Hornby Island, British Columbia, is represented here by a humerus, dorsal vertebrae (including three fused notarial vertebrae), and other fragments. The elements have features typical of Azhdarchoidea, an identification consistent with dominance of this group in the latest Cretaceous. The new material is significant for its size and ontogenetic stage: the humerus and vertebrae indicate a wingspan of ca 1.5 m, but histological sections and bone fusions indicate the individual was approaching maturity at time of death. Pterosaurs of this size are exceedingly rare in Upper Cretaceous strata, a phenomenon commonly attributed to smaller pterosaurs becoming extinct in the Late Cretaceous as part of a reduction in pterosaur diversity and disparity. The absence of small juveniles of large species-which must have existed-in the fossil record is evidence of a preservational bias against small pterosaurs in the Late Cretaceous, and caution should be applied to any interpretation of latest Cretaceous pterosaur diversity and success.
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Affiliation(s)
- Elizabeth Martin-Silverstone
- Ocean and Earth Science, National Oceanography Centre, University of Southampton, European Way, Southampton SO14 3ZH, UK
- School of Earth Sciences, University of Bristol, Wills Memorial Building, Bristol BS8 1RJ, UK
| | - Mark P. Witton
- School of Earth and Environmental Sciences, University of Portsmouth, Burnaby Building, Burnaby Road, Portsmouth PO1 3QL, UK
| | - Victoria M. Arbour
- Paleontology Research Lab, North Carolina Museum of Natural Sciences, Raleigh, NC, USA
- Department of Biological Sciences, North Carolina State University, Raleigh, NC, USA
| | - Philip J. Currie
- Department of Biological Sciences, University of Alberta, Edmonton, Alberta, Canada
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20
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Abstract
Pterosaurs have fascinated scientists and nonscientists alike for over 200 years, as one of the three known clades of vertebrates to have evolved flapping flight. The smallest pterosaurs were comparable in size to the smallest extant birds and bats, but the largest pterosaurs were vastly larger than any extant flier. This immense size range, coupled with poor preservation and adaptations for flight unknown in extant vertebrates, have made interpretations of pterosaur flight problematic and often contentious. Here we review the anatomical, evolutionary, and phylogenetic history of pterosaurs, as well as the views, perspectives, and biases regarding their interpretation. In recent years, three areas of pterosaur biology have faced challenges and made advances: structure of the wing membrane, function of the pteroid, body size and mass estimates, as well as flight mechanics and aerodynamics. Comparative anatomical and fossil study, simulated bone loading, and aerodynamic modeling have all proved successful in furthering our understanding of pterosaur flight. We agree with previous authors that pterosaurs should be studied as pterosaurs, a diverse but phylogenetically, anatomically, and mechanically constrained clade that can offer new insights into the diversity of vertebrate flight.
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Affiliation(s)
- K.M. Middleton
- Department of Pathology and Anatomical Sciences, University of Missouri School of Medicine, Medical Sciences Building M263, 1 Hospital Drive, Columbia, MO 65212, USA
| | - L.T. English
- Jackson School of Geosciences, Department of Geological Sciences, University of Texas at Austin, Austin, TX 78712-1722, USA
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21
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Kolb C, Scheyer TM, Veitschegger K, Forasiepi AM, Amson E, Van der Geer AAE, Van den Hoek Ostende LW, Hayashi S, Sánchez-Villagra MR. Mammalian bone palaeohistology: a survey and new data with emphasis on island forms. PeerJ 2015; 3:e1358. [PMID: 26528418 PMCID: PMC4627922 DOI: 10.7717/peerj.1358] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Accepted: 10/07/2015] [Indexed: 01/31/2023] Open
Abstract
The interest in mammalian palaeohistology has increased dramatically in the last two decades. Starting in 1849 via descriptive approaches, it has been demonstrated that bone tissue and vascularisation types correlate with several biological variables such as ontogenetic stage, growth rate, and ecology. Mammalian bone displays a large variety of bone tissues and vascularisation patterns reaching from lamellar or parallel-fibred to fibrolamellar or woven-fibred bone, depending on taxon and individual age. Here we systematically review the knowledge and methods on cynodont and mammalian bone microstructure as well as palaeohistology and discuss potential future research fields and techniques. We present new data on the bone microstructure of two extant marsupial species and of several extinct continental and island placental mammals. Extant marsupials display mainly parallel-fibred primary bone with radial and oblique but mainly longitudinal vascular canals. Three juvenile specimens of the dwarf island hippopotamid Hippopotamus minor from the Late Pleistocene of Cyprus show reticular to plexiform fibrolamellar bone. The island murid Mikrotia magna from the Late Miocene of Gargano, Italy displays parallel-fibred primary bone with reticular vascularisation and strong remodelling in the middle part of the cortex. Leithia sp., the dormouse from the Pleistocene of Sicily, is characterised by a primary bone cortex consisting of lamellar bone and a high amount of compact coarse cancellous bone. The bone cortex of the fossil continental lagomorph Prolagus oeningensis and three fossil species of insular Prolagus displays mainly parallel-fibred primary bone and reticular, radial as well as longitudinal vascularisation. Typical for large mammals, secondary bone in the giant rhinocerotoid Paraceratherium sp. from the Late Oligocene of Turkey is represented by dense Haversian bone. The skeletochronological features of Sinomegaceros yabei, a large-sized deer from the Pleistocene of Japan closely related to Megaloceros, indicate a high growth rate. These examples and the synthesis of existing data show the potential of bone microstructure to reveal essential information on life history evolution. The bone tissue and the skeletochronological data of the sampled island species suggest the presence of various modes of bone histological modification and mammalian life history evolution on islands to depend on factors of island evolution such as island size, distance from mainland, climate, phylogeny, and time of evolution.
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Affiliation(s)
- Christian Kolb
- Paläontologisches Institut und Museum, Universität Zürich , Zürich , Switzerland
| | - Torsten M Scheyer
- Paläontologisches Institut und Museum, Universität Zürich , Zürich , Switzerland
| | - Kristof Veitschegger
- Paläontologisches Institut und Museum, Universität Zürich , Zürich , Switzerland
| | - Analia M Forasiepi
- Consejo Nacional de Investigaciones Científicas y Técnicas, Instituto Argentino de Nivología, Glaciología y Ciencias Ambientales, Centro Científico y Tecnológico , Mendoza , Argentina
| | - Eli Amson
- Paläontologisches Institut und Museum, Universität Zürich , Zürich , Switzerland
| | - Alexandra A E Van der Geer
- Department of Geology, Naturalis Biodiversity Center , Leiden , The Netherlands ; Department of Historical Geology and Palaeontology, National and Kapodistrian University of Athens , Zografou , Greece
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22
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Hone D, Henderson DM, Therrien F, Habib MB. A specimen of Rhamphorhynchus with soft tissue preservation, stomach contents and a putative coprolite. PeerJ 2015; 3:e1191. [PMID: 26312182 PMCID: PMC4548500 DOI: 10.7717/peerj.1191] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2015] [Accepted: 07/26/2015] [Indexed: 11/20/2022] Open
Abstract
Despite being known for nearly two centuries, new specimens of the derived non-pterodactyloid pterosaur Rhamphorhynchus continue to be discovered and reveal new information about their anatomy and palaeobiology. Here we describe a specimen held in the collections of the Royal Tyrrell Museum of Palaeontology, Alberta, Canada that shows both preservation and impressions of soft tissues, and also preserves material interpreted as stomach contents of vertebrate remains and, uniquely, a putative coprolite. The specimen also preserves additional evidence for fibers in the uropatagium.
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Affiliation(s)
- David Hone
- School of Biological and Chemical Sciences, Queen Mary University of London , London , United Kingdom
| | | | - François Therrien
- Royal Tyrrell Museum of Palaeontology , Drumheller, Alberta , Canada
| | - Michael B Habib
- Keck School of Medicine, University of Southern California , Los Angeles, CA , United States of America
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23
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WANG XIAOLIN, KELLNER ALEXANDERWA, CHENG XIN, JIANG SHUNXING, WANG QIANG, SAYÃO JULIANAM, RODRIGUES TAISSA, COSTA FABIANAR, LI NING, MENG XI, ZHOU ZHONGHE. Eggshell and Histology Provide Insight on the Life History of a Pterosaur with Two Functional Ovaries. ACTA ACUST UNITED AC 2015; 87:1599-609. [DOI: 10.1590/0001-3765201520150364] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
The counterpart of a previously described non-pterodactyloid pterosaur with an egg revealed the presence of a second egg inside the body cavity of this gravid female. It clearly shows that pterosaurs had two functional oviducts and demonstrates that the reduction of one oviduct was not a prerequisite for developing powered flight, at least in this group. Compositional analysis of one egg suggests the lack of a hard external layer of calcium carbonate. Histological sections of one femur lack medullary bone and further demonstrate that this pterosaur reached reproductive maturity before skeletal maturity. This study shows that pterosaurs laid eggs even smaller than previously thought and had a reproductive strategy more similar to basal reptiles than to birds. Whether pterosaurs were highly precocial or needed parental care is still open to debate.
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Affiliation(s)
| | | | - XIN CHENG
- Chinese Academy of Sciences, China; Universidade Federal do Rio de Janeiro, Brazil
| | | | | | | | | | | | - NING LI
- Chinese Academy of Sciences, China; University of Chinese Academy of Sciences, China
| | - XI MENG
- Chinese Academy of Sciences, China
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Tokita M. How the pterosaur got its wings. Biol Rev Camb Philos Soc 2014; 90:1163-78. [PMID: 25361444 DOI: 10.1111/brv.12150] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/26/2014] [Revised: 09/10/2014] [Accepted: 10/01/2014] [Indexed: 12/19/2022]
Abstract
Throughout the evolutionary history of life, only three vertebrate lineages took to the air by acquiring a body plan suitable for powered flight: birds, bats, and pterosaurs. Because pterosaurs were the earliest vertebrate lineage capable of powered flight and included the largest volant animal in the history of the earth, understanding how they evolved their flight apparatus, the wing, is an important issue in evolutionary biology. Herein, I speculate on the potential basis of pterosaur wing evolution using recent advances in the developmental biology of flying and non-flying vertebrates. The most significant morphological features of pterosaur wings are: (i) a disproportionately elongated fourth finger, and (ii) a wing membrane called the brachiopatagium, which stretches from the posterior surface of the arm and elongated fourth finger to the anterior surface of the leg. At limb-forming stages of pterosaur embryos, the zone of polarizing activity (ZPA) cells, from which the fourth finger eventually differentiates, could up-regulate, restrict, and prolong expression of 5'-located Homeobox D (Hoxd) genes (e.g. Hoxd11, Hoxd12, and Hoxd13) around the ZPA through pterosaur-specific exploitation of sonic hedgehog (SHH) signalling. 5'Hoxd genes could then influence downstream bone morphogenetic protein (BMP) signalling to facilitate chondrocyte proliferation in long bones. Potential expression of Fgf10 and Tbx3 in the primordium of the brachiopatagium formed posterior to the forelimb bud might also facilitate elongation of the phalanges of the fourth finger. To establish the flight-adapted musculoskeletal morphology shared by all volant vertebrates, pterosaurs probably underwent regulatory changes in the expression of genes controlling forelimb and pectoral girdle musculoskeletal development (e.g. Tbx5), as well as certain changes in the mode of cell-cell interactions between muscular and connective tissues in the early phase of their evolution. Developmental data now accumulating for extant vertebrate taxa could be helpful in understanding the cellular and molecular mechanisms of body-plan evolution in extinct vertebrates as well as extant vertebrates with unique morphology whose embryonic materials are hard to obtain.
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Affiliation(s)
- Masayoshi Tokita
- Department of Organismic and Evolutionary Biology, Harvard University, 16 Divinity Avenue, Cambridge, MA 02138, U.S.A
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Medullary bone-like tissue in the mandibular symphyses of a pterosaur suggests non-reproductive significance. Sci Rep 2014. [DOI: 10.1038/srep06253] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/08/2022] Open
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Prondvai E, Stein KHW, de Ricqlès A, Cubo J. Development-based revision of bone tissue classification: the importance of semantics for science. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12323] [Citation(s) in RCA: 68] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Affiliation(s)
- Edina Prondvai
- MTA-ELTE Lendület Dinosaur Research Group; Eötvös Loránd University; Pázmány Péter s. 1/c, 1117 Budapest Hungary
| | - Koen H. W. Stein
- Museum für Naturkunde Berlin; Leibniz Institute for Evolution and Biodiversity Science; Invalidenstrasse 43 10115 Berlin Germany
| | - Armand de Ricqlès
- UPMC; UMR 7193, ISTeP; Sorbonne Universités; Univ Paris 06 4 Place Jussieu BC 19 F-75005 Paris France
- CNRS; UMR 7193, ISTeP; 4 place Jussieu BC 19 F-75005 Paris France
| | - Jorge Cubo
- UPMC; UMR 7193, ISTeP; Sorbonne Universités; Univ Paris 06 4 Place Jussieu BC 19 F-75005 Paris France
- CNRS; UMR 7193, ISTeP; 4 place Jussieu BC 19 F-75005 Paris France
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Stein KWH, Werner J. Preliminary analysis of osteocyte lacunar density in long bones of tetrapods: all measures are bigger in sauropod dinosaurs. PLoS One 2013; 8:e77109. [PMID: 24204748 PMCID: PMC3812986 DOI: 10.1371/journal.pone.0077109] [Citation(s) in RCA: 22] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2013] [Accepted: 09/03/2013] [Indexed: 02/04/2023] Open
Abstract
Osteocytes harbour much potential for paleobiological studies. Synchrotron radiation and spectroscopic analyses are providing fascinating data on osteocyte density, size and orientation in fossil taxa. However, such studies may be costly and time consuming. Here we describe an uncomplicated and inexpensive method to measure osteocyte lacunar densities in bone thin sections. We report on cell lacunar densities in the long bones of various extant and extinct tetrapods, with a focus on sauropodomorph dinosaurs, and how lacunar densities can help us understand bone formation rates in the iconic sauropod dinosaurs. Ordinary least square and phylogenetic generalized least square regressions suggest that sauropodomorphs have lacunar densities higher than scaled up or comparably sized mammals. We also found normal mammalian-like osteocyte densities for the extinct bovid Myotragus, questioning its crocodilian-like physiology. When accounting for body mass effects and phylogeny, growth rates are a main factor determining the density of the lacunocanalicular network. However, functional aspects most likely play an important role as well. Observed differences in cell strategies between mammals and dinosaurs likely illustrate the convergent nature of fast growing bone tissues in these groups.
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Affiliation(s)
- Koen W. H. Stein
- Steinmann Institut für Geologie, Mineralogie und Paläontologie, University of Bonn, Bonn, Germany
| | - Jan Werner
- Institut für Zoologie, Abteilung Ökologie, Johannes Gutenberg-Universität Mainz, Mainz, Germany
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Redelstorff R, Hübner TR, Chinsamy A, Sander PM. Bone Histology of the StegosaurKentrosaurus aethiopicus(Ornithischia: Thyreophora) from the Upper Jurassic of Tanzania. Anat Rec (Hoboken) 2013; 296:933-52. [DOI: 10.1002/ar.22701] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2012] [Revised: 02/27/2013] [Accepted: 03/20/2013] [Indexed: 11/11/2022]
Affiliation(s)
- Ragna Redelstorff
- Biological Sciences Department; University of Cape Town; Rhodes Gift, 7701 Cape Town South Africa
| | - Tom R. Hübner
- Niedersächsisches Landesmuseum Hannover; Willy-Brandt-Allee 5 30169 Hanover Germany
| | - Anusuya Chinsamy
- Biological Sciences Department; University of Cape Town; Rhodes Gift, 7701 Cape Town South Africa
| | - P. Martin Sander
- Steinmann Institute for Geology; Mineralogy and Palaeontology, University of Bonn, Nussallee 8; 53115 Bonn Germany
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Ősi A, Prondvai E, Butler R, Weishampel DB. Phylogeny, histology and inferred body size evolution in a new rhabdodontid dinosaur from the Late Cretaceous of Hungary. PLoS One 2012; 7:e44318. [PMID: 23028518 PMCID: PMC3448614 DOI: 10.1371/journal.pone.0044318] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2012] [Accepted: 08/01/2012] [Indexed: 11/24/2022] Open
Abstract
Background Rhabdodontid ornithopod dinosaurs are characteristic elements of Late Cretaceous European vertebrate faunas and were previously collected from lower Campanian to Maastrichtian continental deposits. Phylogenetic analyses have placed rhabdodontids among basal ornithopods as the sister taxon to the clade consisting of Tenontosaurus, Dryosaurus, Camptosaurus, and Iguanodon. Recent studies considered Zalmoxes, the best known representative of the clade, to be significantly smaller than closely related ornithopods such as Tenontosaurus, Camptosaurus, or Rhabdodon, and concluded that it was probably an island dwarf that inhabited the Maastrichtian Haţeg Island. Methodology/Principal Findings Rhabdodontid remains from the Santonian of western Hungary provide evidence for a new, small-bodied form, which we assign to Mochlodon vorosi n. sp. The new species is most similar to the early Campanian M. suessi from Austria, and the close affinities of the two species is further supported by the results of a global phylogenetic analysis of ornithischian dinosaurs. Bone histological studies of representatives of all rhabdodontids indicate a similar adult body length of 1.6–1.8 m in the Hungarian and Austrian species, 2.4–2.5 m in the subadults of both Zalmoxes robustus and Z. shqiperorum and a much larger, 5–6 m adult body length in Rhabdodon. Phylogenetic mapping of femoral lengths onto the results of the phylogenetic analysis suggests a femoral length of around 340 mm as the ancestral state for Rhabdodontidae, close to the adult femoral lengths known for Zalmoxes (320–333 mm). Conclusions/Significance Our analysis of body size evolution does not support the hypothesis of autapomorhic nanism for Zalmoxes. However, Rhabdodon is reconstructed as having undergone autapomorphic giantism and the reconstructed small femoral length (245 mm) of Mochlodon is consistent with a reduction in size relative to the ancestral rhabdodontid condition. Our results imply a pre-Santonian divergence between western and eastern rhabdodontid lineages within the western Tethyan archipelago.
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Affiliation(s)
- Attila Ősi
- Hungarian Academy of Sciences-Eötvös Loránd University, Lendület Dinosaur Research Group, Budapest, Hungary.
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Hone DWE, Tischlinger H, Frey E, Röper M. A new non-pterodactyloid pterosaur from the Late Jurassic of southern Germany. PLoS One 2012; 7:e39312. [PMID: 22792168 PMCID: PMC3390345 DOI: 10.1371/journal.pone.0039312] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2011] [Accepted: 05/17/2012] [Indexed: 11/28/2022] Open
Abstract
Background The ‘Solnhofen Limestone’ beds of the Southern Franconian Alb, Bavaria, southern Germany, have for centuries yielded important pterosaur specimens, most notably of the genera Pterodactylus and Rhamphorhynchus. Here we describe a new genus of non-pterodactyloid pterosaur based on an extremely well preserved fossil of a young juvenile: Bellubrunnus rothgaengeri (gen. et sp. nov.). Methodology/Principal Findings The specimen was examined firsthand by all authors. Additional investigation and photography under UV light to reveal details of the bones not easily seen under normal lighting regimes was completed. Conclusions/Significance This taxon heralds from a newly explored locality that is older than the classic Solnhofen beds. While similar to Rhamphorhynchus, the new taxon differs in the number of teeth, shape of the humerus and femur, and limb proportions. Unlike other derived non-pterodacytyloids, Bellubrunnus lacks elongate chevrons and zygapophyses in the tail, and unlike all other known pterosaurs, the wingtips are curved anteriorly, potentially giving it a unique flight profile.
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Affiliation(s)
- David W E Hone
- Department of Biology and Environmental Sciences, University College Dublin, Dublin, Ireland.
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