1
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Miller E, Lee HW, Abzhanov A, Evers SW. The topological organization of the turtle cranium is constrained and conserved over long evolutionary timescales. Anat Rec (Hoboken) 2024; 307:2713-2748. [PMID: 38102921 DOI: 10.1002/ar.25356] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2023] [Revised: 10/30/2023] [Accepted: 11/14/2023] [Indexed: 12/17/2023]
Abstract
The cranium of turtles (Testudines) is characterized by the secondary reduction of temporal fenestrae and loss of cranial joints (i.e., characteristics of anapsid, akinetic skulls). Evolution and ontogeny of the turtle cranium are associated with shape changes. Cranial shape variation among Testudines can partially be explained by dietary and functional adaptations (neck retraction), but it is unclear if cranial topology shows similar ecomorphological signal, or if it is decoupled from shape evolution. We assess the topological arrangement of cranial bones (i.e., number, relative positioning, connections), using anatomical network analysis. Non-shelled stem turtles have similar cranial arrangements to archosauromorph outgroups. Shelled turtles (Testudinata) evolve a unique cranial organization that is associated with bone losses (e.g., supratemporal, lacrimal, ectopterygoid) and an increase in complexity (i.e., densely and highly interconnected skulls with low path lengths between bones), resulting from the closure of skull openings and establishment of unusual connections such as a parietal-pterygoid contact in the secondary braincase. Topological changes evolutionarily predate many shape changes. Topological variation and taxonomic morphospace discrimination among crown turtles are low, indicating that cranial topology may be constrained. Observed variation results from repeated losses of nonintegral bones (i.e., premaxilla, nasal, epipterygoid, quadratojugal), and changes in temporal emarginations and palate construction. We observe only minor ontogenetic changes. Topology is not influenced by diet and habitat, contrasting cranial shape. Our results indicate that turtles have a unique cranial topology among reptiles that is conserved after its initial establishment, and shows that cranial topology and shape have different evolutionary histories.
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Affiliation(s)
- Eve Miller
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Berkshire, UK
- Natural History Museum, London, UK
| | - Hiu Wai Lee
- Department of Earth Sciences, The University of Hong Kong, Hong Kong SAR, China
| | - Arkhat Abzhanov
- Department of Life Sciences, Imperial College London, Silwood Park Campus, Berkshire, UK
- Natural History Museum, London, UK
| | - Serjoscha W Evers
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
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2
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Wolniewicz AS, Shen Y, Li Q, Sun Y, Qiao Y, Chen Y, Hu YW, Liu J. An armoured marine reptile from the Early Triassic of South China and its phylogenetic and evolutionary implications. eLife 2023; 12:e83163. [PMID: 37551884 PMCID: PMC10499374 DOI: 10.7554/elife.83163] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2022] [Accepted: 08/07/2023] [Indexed: 08/09/2023] Open
Abstract
Sauropterygia was a taxonomically and ecomorphologically diverse clade of Mesozoic marine reptiles spanning the Early Triassic to the Late Cretaceous. Sauropterygians are traditionally divided into two groups representing two markedly different body plans - the short-necked, durophagous Placodontia and the long-necked Eosauropterygia - whereas Saurosphargidae, a small clade of armoured marine reptiles, is generally considered as the sauropterygian sister-group. However, the early evolutionary history of sauropterygians and their phylogenetic relationships with other groups within Diapsida are still incompletely understood. Here, we report a new saurosphargid from the Early Triassic (Olenekian) of South China - Prosaurosphargis yingzishanensis gen. et sp. nov. - representing the earliest known occurrence of the clade. An updated phylogenetic analysis focussing on the interrelationships among diapsid reptiles recovers saurosphargids as nested within sauropterygians, forming a clade with eosauropterygians to the exclusion of placodonts. Furthermore, a clade comprising Eusaurosphargis and Palatodonta is recovered as the sauropterygian sister-group within Sauropterygomorpha tax. nov. The phylogenetic position of several Early and Middle Triassic sauropterygians of previously uncertain phylogenetic affinity, such as Atopodentatus, Hanosaurus, Majiashanosaurus, and Corosaurus, is also clarified, elucidating the early evolutionary assembly of the sauropterygian body plan. Finally, our phylogenetic analysis supports the placement of Testudines and Archosauromorpha within Archelosauria, a result strongly corroborated by molecular data, but only recently recovered in a phylogenetic analysis using a morphology-only dataset. Our study provides evidence for the rapid diversification of sauropterygians in the aftermath of the Permo-Triassic mass extinction event and emphasises the importance of broad taxonomic sampling in reconstructing phylogenetic relationships among extinct taxa.
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Affiliation(s)
- Andrzej S Wolniewicz
- School of Resources and Environmental Engineering, Hefei University of TechnologyHefeiChina
- Institute of Paleobiology, Polish Academy of SciencesWarsawPoland
| | - Yuefeng Shen
- School of Resources and Environmental Engineering, Hefei University of TechnologyHefeiChina
| | - Qiang Li
- School of Resources and Environmental Engineering, Hefei University of TechnologyHefeiChina
- Section Paleontology, Institute of Geosciences, University of BonnBonnGermany
| | - Yuanyuan Sun
- Chengdu Center, China Geological Survey (Southwest China Innovation Center for Geosciences)ChengduChina
| | - Yu Qiao
- School of Resources and Environmental Engineering, Hefei University of TechnologyHefeiChina
| | - Yajie Chen
- School of Resources and Environmental Engineering, Hefei University of TechnologyHefeiChina
| | - Yi-Wei Hu
- School of Resources and Environmental Engineering, Hefei University of TechnologyHefeiChina
| | - Jun Liu
- School of Resources and Environmental Engineering, Hefei University of TechnologyHefeiChina
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3
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Scheyer TM, Klein N, Evers SW, Mautner AK, Pabst B. First evidence of Proganochelys quenstedtii (Testudinata) from the Plateosaurus bonebeds (Norian, Late Triassic) of Frick, Canton Aargau, Switzerland. SWISS JOURNAL OF PALAEONTOLOGY 2022; 141:17. [PMID: 36317153 PMCID: PMC9613585 DOI: 10.1186/s13358-022-00260-4] [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: 06/27/2022] [Accepted: 09/15/2022] [Indexed: 06/16/2023]
Abstract
UNLABELLED Proganochelys quenstedtii represents the best-known stem turtle from the Late Triassic, with gross anatomical and internal descriptions of the shell, postcranial bones and skull based on several well-preserved specimens from Central European fossil locations. We here report on the first specimen of P. quenstedtii from the Late Triassic (Klettgau Formation) Frickberg near the town of Frick, Canton Aargau, Switzerland. Similar to other Late Triassic 'Plateosaurus-bearing bonebeds', Proganochelys is considered to be a rare faunal element in the Swiss locality of Frick as well. The specimen, which is largely complete but was found only partially articulated and mixed with large Plateosaurus bones, overall resembles the morphology of the classical specimens from Germany. Despite being disarticulated, most skull bones could be identified and micro-computed tomography (CT) scanning of the posterior skull region reveals new insights into the braincase and neurovascular anatomy, as well as the inner ear region. These include the presence of a fenestra perilymphatica, potentially elongated cochlear ducts, and intense vascularization of small tubercles on the posterior end of the skull roof, which we interpret as horn cores. Other aspects of the skull in the braincase region, such as the presence or absence of a supratemporal remain ambiguous due to the fusion of individual bones and thus lack of visible sutures (externally and internally). Based on the size of the shell and fusion of individual elements, the specimen is interpreted as a skeletally mature animal. SUPPLEMENTARY INFORMATION The online version contains supplementary material available at 10.1186/s13358-022-00260-4.
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Affiliation(s)
- Torsten M. Scheyer
- Palaeontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
| | - Nicole Klein
- Palaeontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
- Institute of Geosciences, Paleontology, University of Bonn, Nussallee 8, 53115 Bonn, Germany
| | - Serjoscha W. Evers
- Department of Geosciences, University of Fribourg, Ch. du Musée 6, 1700 Fribourg, Switzerland
| | - Anna-Katharina Mautner
- Palaeontological Institute and Museum, University of Zurich, Karl-Schmid-Strasse 4, 8006 Zurich, Switzerland
| | - Ben Pabst
- Sauriermuseum Aathal, Zürichstrasse 69, 8607 Aathal-Seegräben, Switzerland
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4
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Simões TR, Kammerer CF, Caldwell MW, Pierce SE. Successive climate crises in the deep past drove the early evolution and radiation of reptiles. SCIENCE ADVANCES 2022; 8:eabq1898. [PMID: 35984885 PMCID: PMC9390993 DOI: 10.1126/sciadv.abq1898] [Citation(s) in RCA: 12] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/13/2023]
Abstract
Climate change-induced mass extinctions provide unique opportunities to explore the impacts of global environmental disturbances on organismal evolution. However, their influence on terrestrial ecosystems remains poorly understood. Here, we provide a new time tree for the early evolution of reptiles and their closest relatives to reconstruct how the Permian-Triassic climatic crises shaped their long-term evolutionary trajectory. By combining rates of phenotypic evolution, mode of selection, body size, and global temperature data, we reveal an intimate association between reptile evolutionary dynamics and climate change in the deep past. We show that the origin and phenotypic radiation of reptiles was not solely driven by ecological opportunity following the end-Permian extinction as previously thought but also the result of multiple adaptive responses to climatic shifts spanning 57 million years.
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Affiliation(s)
- Tiago R. Simões
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford St., Cambridge, MA 02138, USA
- Corresponding author.
| | - Christian F. Kammerer
- North Carolina Museum of Natural Sciences, 11 W. Jones Street, Raleigh, NC 27601, USA
- Department of Biological Sciences, North Carolina State University, Campus Box 7617, Raleigh, NC 27695, USA
| | - Michael W. Caldwell
- Department of Biological Sciences, University of Alberta, 11645 Saskatchewan Drive, Edmonton, Alberta T6G 2E9, Canada
- Department of Earth and Atmospheric Sciences, University of Alberta, 11645 Saskatchewan Drive, Edmonton, Alberta T6G 2E9, Canada
| | - Stephanie E. Pierce
- Museum of Comparative Zoology and Department of Organismic and Evolutionary Biology, Harvard University, 26 Oxford St., Cambridge, MA 02138, USA
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5
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Ascarrunz E, Sánchez-Villagra MR. The macroevolutionary and developmental evolution of the turtle carapacial scutes. VERTEBRATE ZOOLOGY 2022. [DOI: 10.3897/vz.72.e76256] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/12/2022]
Abstract
The scutes of the carapace of extant turtles exhibit common elements in a narrow range of topographical arrangements. The typical arrangement has remained constant since its origin in the clade Mesochelydia (Early Jurassic), after a period of apparent greater diversity in the Triassic. This contribution is a review of the development and evolutionary history of the scute patterns of the carapace, seen through the lens of recent developmental models. This yields insights on pattern variations in the fossil record. We reinterpret the “supracaudal” scute and propose that Proganochelys had five vertebral scutes. We discuss the relationship between supramarginal scutes and Turing processes, and we show how a simple change during embryogenesis could account for origin of the configuration of the caudal region of the carapace in mesochelydians. We also discuss the nature of the decrease in number of scutes over the course of evolution, and whether macroevolutionary trends can be discerned. We argue that turtles with complete loss of scutes (e.g., softshells) follow clade-specific macroevolutionary regimes, which are distinct from the majority of other turtles. Finally, we draw a parallel between the variation of scute patterns on the carapace of turtles and the scale patterns in the pileus region (roof of the head) of squamates. The size and numbers of scales in the pileus region can evolve over a wide range, but we recognized tentative evidence of convergence towards a typical configuration when the scales become larger and fewer. Thus, typical patterns could be a more general property of similar systems of integumentary appendages.
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6
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Global Analysis of Transcriptome and Translatome Revealed That Coordinated WNT and FGF Regulate the Carapacial Ridge Development of Chinese Soft-Shell Turtle. Int J Mol Sci 2021; 22:ijms222212441. [PMID: 34830331 PMCID: PMC8621500 DOI: 10.3390/ijms222212441] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2021] [Revised: 11/14/2021] [Accepted: 11/15/2021] [Indexed: 12/16/2022] Open
Abstract
The turtle carapace is composed of severely deformed fused dorsal vertebrae, ribs, and bone plates. In particular, the lateral growth in the superficial layer of turtle ribs in the dorsal trunk causes an encapsulation of the scapula and pelvis. The recent study suggested that the carapacial ridge (CR) is a new model of epithelial–mesenchymal transition which is essential for the arrangement of the ribs. Therefore, it is necessary to explore the regulatory mechanism of carapacial ridge development to analyze the formation of the turtle shell. However, the current understanding of the regulatory network underlying turtle carapacial ridge development is poor due to the lack of both systematic gene screening at different carapacial ridge development stages and gene function verification studies. In this study, we obtained genome-wide gene transcription and gene translation profiles using RNA sequencing and ribosome nascent-chain complex mRNA sequencing from carapacial ridge tissues of Chinese soft-shell turtle at different development stages. A correlation analysis of the transcriptome and translatome revealed that there were 129, 670, and 135 codifferentially expressed genes, including homodirection and opposite-direction differentially expressed genes, among three comparison groups, respectively. The pathway enrichment analysis of codifferentially expressed genes from the Kyoto Encyclopedia of Genes and Genomes showed dynamic changes in signaling pathways involved in carapacial ridge development. Especially, the results revealed that the Wnt signaling pathway and MAPK signaling pathway may play important roles in turtle carapacial ridge development. In addition, Wnt and Fgf were expressed during the carapacial ridge development. Furthermore, we discovered that Wnt5a regulated carapacial ridge development through the Wnt5a/JNK pathway. Therefore, our studies uncover that the morphogenesis of the turtle carapace might function through the co-operation between conserved WNT and FGF signaling pathways. Consequently, our findings revealed the dynamic signaling pathways acting on the carapacial ridge development of Chinese soft-shell turtle and provided new insights into uncover the molecular mechanism underlying turtle shell morphogenesis.
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7
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An B, Sun W, Zhang D. Role of soft bi-layer coating on the protection of turtle carapace. J Biomech 2021; 126:110618. [PMID: 34274868 DOI: 10.1016/j.jbiomech.2021.110618] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/29/2020] [Revised: 06/07/2021] [Accepted: 07/05/2021] [Indexed: 11/20/2022]
Abstract
The turtle carapace is a biological armor exhibiting enhanced protection performance. Despite considerable efforts to characterize the structure-property relations of the turtle carapace, how the design of soft keratin-collagen bi-layer coating contributes to the protection of this biological armor remains largely unknown. In this study, calculations are carried out for fracture of the turtle carapace subjected to impact loading. The dynamic fracture of the bone layer, plastic deformation of the keratin-collagen bi-layer, and delamination at the keratin-collagen and collagen-bone interfaces are accounted for in the analyses. We reveal that plastic deformation and interfacial delamination within the soft bi-layer coating are two toughening mechanisms controlling the resistance to dynamic crack growth in the bone layer of the turtle carapace. The architecture of the keratin-collagen bi-layer coating enables large plastic deformation in the collagen layer and multiple delaminations within the bi-layer coating, preventing crack propagation in the bone layer. It is found that the dynamic fracture of bone layer in the turtle carapace depends on the stiffness mismatch and yield stress contrast between the keratin layer and the collagen layer. As the stiffness mismatch increases, small plastic deformation of the bi-layer coating occurs and the plastic deformation of collagen layer tends to emerge in the vicinity of the keratin-collagen interface, suppressing interfacial delamination and leading to weak resistance to fracture of the bone layer. The intermediate level of yield stress contrast can activate large plastic deformation and multiple delaminations within the bi-layer coating, mitigating fracture of the bone layer.
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Affiliation(s)
- Bingbing An
- Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Institute of Applied Mathematics and Mechanics, School of Mechanics and Engineering Science, Shanghai University, Shanghai 200444, China.
| | - Wenhao Sun
- Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Institute of Applied Mathematics and Mechanics, School of Mechanics and Engineering Science, Shanghai University, Shanghai 200444, China
| | - Dongsheng Zhang
- Shanghai Key Laboratory of Mechanics in Energy Engineering, Shanghai Institute of Applied Mathematics and Mechanics, School of Mechanics and Engineering Science, Shanghai University, Shanghai 200444, China
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8
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Radermacher VJ, Fernandez V, Schachner ER, Butler RJ, Bordy EM, Naylor Hudgins M, de Klerk WJ, Chapelle KE, Choiniere JN. A new Heterodontosaurus specimen elucidates the unique ventilatory macroevolution of ornithischian dinosaurs. eLife 2021; 10:66036. [PMID: 34225841 PMCID: PMC8260226 DOI: 10.7554/elife.66036] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2020] [Accepted: 05/24/2021] [Indexed: 01/21/2023] Open
Abstract
Ornithischian dinosaurs were ecologically prominent herbivores of the Mesozoic Era that achieved a global distribution by the onset of the Cretaceous. The ornithischian body plan is aberrant relative to other ornithodiran clades, and crucial details of their early evolution remain obscure. We present a new, fully articulated skeleton of the early branching ornithischian Heterodontosaurus tucki. Phase-contrast enhanced synchrotron data of this new specimen reveal a suite of novel postcranial features unknown in any other ornithischian, with implications for the early evolution of the group. These features include a large, anteriorly projecting sternum; bizarre, paddle-shaped sternal ribs; and a full gastral basket – the first recovered in Ornithischia. These unusual anatomical traits provide key information on the evolution of the ornithischian body plan and suggest functional shifts in the ventilatory apparatus occurred close to the base of the clade. We complement these anatomical data with a quantitative analysis of ornithischian pelvic architecture, which allows us to make a specific, stepwise hypothesis for their ventilatory evolution. The fossilised skeletons of long extinct dinosaurs are more than just stones. By comparing these remains to their living relatives such as birds and crocodiles, palaeontologists can reveal how dinosaurs grew, moved, ate and socialised. Previous research indicates that dinosaurs were likely warm-blooded and also more active than modern reptiles. This means they would have required breathing mechanisms capable of supplying enough oxygen to allow these elevated activity levels. So far, much of our insight into dinosaur breathing biology has been biased towards dinosaur species more closely related to modern birds, such as Tyrannosaurus rex, as well as the long-necked sauropods. The group of herbivorous dinosaurs known as ornithischians, which include animals with head ornamentation, spikes and heavy body armour, like that found in Triceratops and Stegosaurus, have often been overlooked. As a result, there are still significant gaps in ornithischian biology, especially in understanding how they breathed. Radermacher et al. used high-powered X-rays to study a new specimen of the most primitive ornithischian dinosaur, Heterodontosaurus tucki, and discovered that this South African dinosaur has bones researchers did not know existed in this species. These include bones that are part of the breathing system of extant reptiles and birds, including toothpick-shaped bones called gastralia, paired sternal bones and sternal ribs shaped like tennis rackets. Together, these new pieces of anatomy form a complicated chest skeleton with a large range of motion that would have allowed the body to expand during breathing cycles. But this increased motion of the chest was only possible in more primitive ornithischians. More advanced species lost much of the anatomy that made this motion possible. Radermacher et al. show that while the chest was simpler in advanced species, their pelvis was more specialised and likely played a role in breathing as it does in modern crocodiles. This new discovery could inform the work of biologists who study the respiratory diversity of both living and extinct species. Differences in breathing strategies might be one of the underlying reasons that some lineages of animals go extinct. It could explain why some species do better than others under stressful conditions, like when the climate is warmer or has less oxygen.
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Affiliation(s)
- Viktor J Radermacher
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.,Department of Earth and Environmental Sciences, University of Minnesota, Minneapolis, United States
| | - Vincent Fernandez
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.,European Synchrotron Radiation Facility, Grenoble, France.,Natural History Museum, Imaging and Analysis Centre, London, United Kingdom
| | - Emma R Schachner
- Department of Cell Biology & Anatomy, School of Medicine, Louisiana State University Health Sciences Center, New Orleans, United States
| | - Richard J Butler
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.,School of Geography, Earth and Environmental Sciences, University of Birmingham, Birmingham, United Kingdom
| | - Emese M Bordy
- Department of Geological Sciences, University of Cape Town, Cape Town, South Africa
| | | | - William J de Klerk
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.,Department of Earth Sciences, Albany Museum, Grahamstown, South Africa
| | - Kimberley Ej Chapelle
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa.,Division of Paleontology, American Museum of Natural History, New York, United States
| | - Jonah N Choiniere
- Evolutionary Studies Institute, University of the Witwatersrand, Johannesburg, South Africa
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9
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Dziomber L, Joyce WG, Foth C. The ecomorphology of the shell of extant turtles and its applications for fossil turtles. PeerJ 2020; 8:e10490. [PMID: 33391873 PMCID: PMC7761203 DOI: 10.7717/peerj.10490] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/04/2020] [Accepted: 11/13/2020] [Indexed: 11/20/2022] Open
Abstract
Turtles are a successful clade of reptiles that originated in the Late Triassic. The group adapted during its evolution to different types of environments, ranging from dry land to ponds, rivers, and the open ocean, and survived all Mesozoic and Cenozoic extinction events. The body of turtles is characterized by a shell, which has been hypothesized to have several biological roles, like protection, thermal and pH regulation, but also to be adapted in its shape to the ecology of the animal. However, only few studies have investigated the relationships between shell shape and ecology in a global context or clarified if shape can be used to diagnose habitat preferences in fossil representatives. Here, we assembled a three-dimensional dataset of 69 extant turtles and three fossils, in particular, the Late Triassic Proganochelys quenstedtii and Proterochersis robusta and the Late Jurassic Plesiochelys bigleri to test explicitly for a relationship between shell shape and ecology. 3D models were obtained using surface scanning and photogrammetry. The general shape of the shells was captured using geometric morphometrics. The habitat ecology of extant turtles was classified using the webbing of their forelimbs as a proxy. Principal component analysis (PCA) highlights much overlap between habitat groups. Discriminant analyses suggests significant differences between extant terrestrial turtles, extant fully aquatic (i.e., marine and riverine) turtles, and an unspecialized assemblage that includes extant turtles from all habitats, mostly freshwater aquatic forms. The paleoecology of the three fossil species cannot be determined with confidence, as all three fall within the unspecialized category, even if Plesiochelys bigleri plots closer to fully aquatic turtles, while the two Triassic species group closer to extant terrestrial forms. Although the shape of the shell of turtles indeed contains an ecological signal, it is overall too weak to uncover using shell shape in paleoecological studies, at least with the methods we selected.
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Affiliation(s)
- Laura Dziomber
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
- Institute of Plant Sciences & Oeschger Centre for Climate Change Research, University of Bern, Bern, Switzerland
| | - Walter G. Joyce
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Christian Foth
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
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10
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Draft Genome of the Common Snapping Turtle, Chelydra serpentina, a Model for Phenotypic Plasticity in Reptiles. G3-GENES GENOMES GENETICS 2020; 10:4299-4314. [PMID: 32998935 PMCID: PMC7718744 DOI: 10.1534/g3.120.401440] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Turtles are iconic reptiles that inhabit a range of ecosystems from oceans to deserts and climates from the tropics to northern temperate regions. Yet, we have little understanding of the genetic adaptations that allow turtles to survive and reproduce in such diverse environments. Common snapping turtles, Chelydra serpentina, are an ideal model species for studying adaptation to climate because they are widely distributed from tropical to northern temperate zones in North America. They are also easy to maintain and breed in captivity and produce large clutch sizes, which makes them amenable to quantitative genetic and molecular genetic studies of traits like temperature-dependent sex determination. We therefore established a captive breeding colony and sequenced DNA from one female using both short and long reads. After trimming and filtering, we had 209.51Gb of Illumina reads, 25.72Gb of PacBio reads, and 21.72 Gb of Nanopore reads. The assembled genome was 2.258 Gb in size and had 13,224 scaffolds with an N50 of 5.59Mb. The longest scaffold was 27.24Mb. BUSCO analysis revealed 97.4% of core vertebrate genes in the genome. We identified 3.27 million SNPs in the reference turtle, which indicates a relatively high level of individual heterozygosity. We assembled the transcriptome using RNA-Seq data and used gene prediction software to produce 22,812 models of protein coding genes. The quality and contiguity of the snapping turtle genome is similar to or better than most published reptile genomes. The genome and genetic variants identified here provide a foundation for future studies of adaptation to climate.
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11
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Sena MVDA, Bantim RAM, Saraiva AÁF, Sayão JM, Oliveira GR. Osteohistology and microanatomy of a new specimen of Cearachelys placidoi (Testudines: Pleurodira) a side-necked turtle from the lower Cretaceous of Brazil. Anat Rec (Hoboken) 2020; 304:1294-1304. [PMID: 33103362 DOI: 10.1002/ar.24556] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/18/2020] [Accepted: 09/15/2020] [Indexed: 11/10/2022]
Abstract
Pelomedusoides had a recognised diverse Early Cretaceous fauna of turtles in Northeast Brazil. Within them, the bothremydid Cearachelys placidoi has a relatively abundant record. This diversity contrasts with the scarcity of osteohistological studies in this group. The relatively well-preserved shell of C. placidoi (UFRPE 5600), from the Aptian age of Araripe Basin, is studied here for the purpose of filling this gap. We performed the osteohistological description of the plastron of a new specimen of C. placidoi. Also, to conduct a comparative study, we carried out histological sections in bones of the recent chelid Phrynops sp. Our histological findings indicate similarities between the histological pattern of freshwater turtles and the coastal marine C. placidoi. Moreover, osteohistological features imply metaplastic incorporation of dermal interwoven structural fiber bundles. Lastly, the xiphiplastron of C. placidoi shows an increase of bone compactness over its craniocaudal axis. This microanatomical feature is exclusive to Cearachelys so far.
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Affiliation(s)
- Mariana Valéria de Araújo Sena
- Programa de Pós-Graduação em Geociências (PPGEOC), Departamento de Geologia, Universidade Federal de Pernambuco, Avenida Prof. Moraes Rego, 1235, Recife, Pernambuco, 50670-901, Brazil.,Centro Universitário da Vitória de Santo Antão, Loteamento São Vicente Ferrer, 71, Vitória de Santo Antão, Pernambuco, 55610-050, Brazil
| | - Renan Alfredo Machado Bantim
- Laboratório de Paleontologia da URCA, Universidade Regional do Cariri, Rua Carolino Sucupira, s/nº, Crato, Ceará, 63105-000, Brazil
| | - Antônio Álamo Feitosa Saraiva
- Laboratório de Paleontologia da URCA, Universidade Regional do Cariri, Rua Carolino Sucupira, s/nº, Crato, Ceará, 63105-000, Brazil
| | - Juliana Manso Sayão
- Laboratório de Paleobiologia e Paleogeografia Antártica, Museu Nacional, Universidade Federal do Rio de Janeiro, Quinta da Boa Vista s/nº, Rio de Janeiro, Rio de Janeiro, 20940-040, Brazil
| | - Gustavo Ribeiro Oliveira
- Laboratório de Paleontologia & Sistemática, Departamento de Biologia, Universidade Federal Rural de Pernambuco, Rua Dom Manoel de Medeiros, s/nº, Recife, Pernambuco, 52171-900, Brazil
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12
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Lyson TR, Bever GS. Origin and Evolution of the Turtle Body Plan. ANNUAL REVIEW OF ECOLOGY, EVOLUTION, AND SYSTEMATICS 2020. [DOI: 10.1146/annurev-ecolsys-110218-024746] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
The origin of turtles and their uniquely shelled body plan is one of the longest standing problems in vertebrate biology. The unfulfilled need for a hypothesis that both explains the derived nature of turtle anatomy and resolves their unclear phylogenetic position among reptiles largely reflects the absence of a transitional fossil record. Recent discoveries have dramatically improved this situation, providing an integrated, time-calibrated model of the morphological, developmental, and ecological transformations responsible for the modern turtle body plan. This evolutionary trajectory was initiated in the Permian (>260 million years ago) when a turtle ancestor with a diapsid skull evolved a novel mechanism for lung ventilation. This key innovation permitted the torso to become apomorphically stiff, most likely as an adaption for digging and a fossorial ecology. The construction of the modern turtle body plan then proceeded over the next 100 million years following a largely stepwise model of osteological innovation.
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Affiliation(s)
- Tyler R. Lyson
- Department of Earth Sciences, Denver Museum of Nature & Science, Denver, Colorado 80205, USA
| | - Gabriel S. Bever
- Department of Earth Sciences, Denver Museum of Nature & Science, Denver, Colorado 80205, USA
- Center for Functional Anatomy and Evolution, Johns Hopkins University School of Medicine, Baltimore, Maryland 21205, USA
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13
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Clark-Hachtel CM, Tomoyasu Y. Two sets of candidate crustacean wing homologues and their implication for the origin of insect wings. Nat Ecol Evol 2020; 4:1694-1702. [PMID: 32747770 DOI: 10.1038/s41559-020-1257-8] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/13/2019] [Accepted: 06/24/2020] [Indexed: 12/24/2022]
Abstract
The origin of insect wings is a biological mystery that has fascinated scientists for centuries. Identification of tissues homologous to insect wings from lineages outside of Insecta will provide pivotal information to resolve this conundrum. Here, through expression and clustered regularly interspaced short palindromic repeats (CRISPR)-CRISPR-associated protein 9 (Cas9) functional analyses in Parhyale, we show that a gene network similar to the insect wing gene network (preWGN) operates both in the crustacean terga and in the proximal leg segments, suggesting that the evolution of a preWGN precedes the emergence of insect wings, and that from an evo-devo perspective, both of these tissues qualify as potential crustacean wing homologues. Combining these results with recent wing origin studies in insects, we discuss the possibility that both tissues are crustacean wing homologues, which supports a dual evolutionary origin of insect wings (that is, novelty through a merger of two distinct tissues). These outcomes have a crucial impact on the course of the intellectual battle between the two historically competing wing origin hypotheses.
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Affiliation(s)
- Courtney M Clark-Hachtel
- Department of Biology, Miami University, Oxford, OH, USA.,Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
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14
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Colston TJ, Kulkarni P, Jetz W, Pyron RA. Phylogenetic and spatial distribution of evolutionary diversification, isolation, and threat in turtles and crocodilians (non-avian archosauromorphs). BMC Evol Biol 2020; 20:81. [PMID: 32650718 PMCID: PMC7350713 DOI: 10.1186/s12862-020-01642-3] [Citation(s) in RCA: 24] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2019] [Accepted: 06/17/2020] [Indexed: 12/29/2022] Open
Abstract
Background The origin of turtles and crocodiles and their easily recognized body forms dates to the Triassic and Jurassic. Despite their long-term success, extant species diversity is low, and endangerment is extremely high compared to other terrestrial vertebrate groups, with ~ 65% of ~ 25 crocodilian and ~ 360 turtle species now threatened by exploitation and habitat loss. Here, we combine available molecular and morphological evidence with statistical and machine learning algorithms to present a phylogenetically informed, comprehensive assessment of diversification, threat status, and evolutionary distinctiveness of all extant species. Results In contrast to other terrestrial vertebrates and their own diversity in the fossil record, the recent extant lineages of turtles and crocodilians have not experienced any global mass extinctions or lineage-wide shifts in diversification rate or body-size evolution over time. We predict threat statuses for 114 as-yet unassessed or data-deficient species and identify a concentration of threatened turtles and crocodilians in South and Southeast Asia, western Africa, and the eastern Amazon. We find that unlike other terrestrial vertebrate groups, extinction risk increases with evolutionary distinctiveness: a disproportionate amount of phylogenetic diversity is concentrated in evolutionarily isolated, at-risk taxa, particularly those with small geographic ranges. Our findings highlight the important role of geographic determinants of extinction risk, particularly those resulting from anthropogenic habitat-disturbance, which affect species across body sizes and ecologies. Conclusions Extant turtles and crocodilians maintain unique, conserved morphologies which make them globally recognizable. Many species are threatened due to exploitation and global change. We use taxonomically complete, dated molecular phylogenies and various approaches to produce a comprehensive assessment of threat status and evolutionary distinctiveness of both groups. Neither group exhibits significant overall shifts in diversification rate or body-size evolution, or any signature of global mass extinctions in recent, extant lineages. However, the most evolutionarily distinct species tend to be the most threatened, and species richness and extinction risk are centered in areas of high anthropogenic disturbance, particularly South and Southeast Asia. Range size is the strongest predictor of threat, and a disproportionate amount of evolutionary diversity is at risk of imminent extinction.
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Affiliation(s)
- Timothy J Colston
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA. .,Present address: Department of Biological Science, Florida State University, Tallahassee, FL, 32304, USA.
| | | | - Walter Jetz
- Center for Biodiversity and Global Change, Yale University, New Haven, CT, 06511, USA.,Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT, 06511, USA
| | - R Alexander Pyron
- Department of Biological Sciences, The George Washington University, Washington, DC, 20052, USA
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15
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Ampaw E, Owoseni TA, Du F, Pinilla N, Obayemi J, Hu J, Nigay PM, Nzihou A, Uzonwanne V, Zebaze-Kana MG, Dewoolkar M, Tan T, Soboyejo W. Compressive deformation and failure of trabecular structures in a turtle shell. Acta Biomater 2019; 97:535-543. [PMID: 31310853 DOI: 10.1016/j.actbio.2019.07.023] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2019] [Revised: 07/08/2019] [Accepted: 07/11/2019] [Indexed: 12/22/2022]
Abstract
Turtle shells comprising of cortical and trabecular bones exhibit intriguing mechanical properties. In this work, compression tests were performed using specimens made from the carapace of Kinixys erosa turtle. A combination of imaging techniques and mechanical testing were employed to examine the responses of hierarchical microstructures of turtle shell under compression. Finite element models produced from microCT-scanned microstructures and analytical foam structure models were then used to elucidate local responses of trabecular bones deformed under compression. The results reveal the contributions from micro-strut bending and stress concentrations to the fractural mechanisms of trabecular bone structures. The porous structures of turtle shells could be an excellent prototype for the bioinspired design of deformation-resistant structures. STATEMENT OF SIGNIFICANCE: In this study, a combination of analytical, computational models and experiments is used to study the underlying mechanisms that contribute to the compressive deformation of a Kinixys erosa turtle shell between the nano-, micro- and macro-scales. The proposed work shows that the turtle shell structures can be analyzed as sandwich structures that have the capacity to concentrate deformation and stresses within the trabecular bones, which enables significant energy absorption during compressive deformation. Then, the trends in the deformation characteristics and the strengths of the trabecular bone segments are well predicted by the four-strut model, which captures the effects of variations in strut length, thickness and orientation that are related to microstructural uncertainties of the turtle shells. The above results also suggest that the model may be used to guide the bioinspired design of sandwich porous structures that mimic the properties of the cortical and trabecular bone segments of turtle shells under a range of loading conditions.
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Affiliation(s)
- Edward Ampaw
- Department of Materials Science and Engineering, African University of Science and Technology, Nigeria; Department of Mechanical Engineering, Koforidua Technical University, Koforidua, Ghana
| | - Tunji Adetayo Owoseni
- Department of Materials Science and Engineering, African University of Science and Technology, Nigeria
| | - Fen Du
- Department of Mechanical Engineering, Vermont Technical College, Randolph Center, VT 05061, USA
| | - Nelson Pinilla
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08540, USA
| | - John Obayemi
- Department of Mechanical Engineering, Worcester Polytechnic Institute, MA 01609, USA
| | - Jingjie Hu
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08540, USA
| | - Pierre-Marie Nigay
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08540, USA; Department of Mechanical Engineering, Worcester Polytechnic Institute, MA 01609, USA
| | - Ange Nzihou
- Department of Chemical Engineering, Université de Toulouse, Mines Albi, CNRS UMR 5302, Centre RAPSODEE, F-81013 Albi Cedex 09, France
| | - Vanessa Uzonwanne
- Department of Mechanical Engineering, Worcester Polytechnic Institute, MA 01609, USA
| | | | - Mandar Dewoolkar
- Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT 05405, USA
| | - Ting Tan
- Department of Civil and Environmental Engineering, University of Vermont, Burlington, VT 05405, USA
| | - Winston Soboyejo
- Department of Mechanical and Aerospace Engineering, Princeton University, Princeton, NJ 08540, USA; Department of Mechanical Engineering, Worcester Polytechnic Institute, MA 01609, USA.
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16
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Schoch RR, Klein N, Scheyer TM, Sues HD. Microanatomy of the stem-turtle Pappochelys rosinae indicates a predominantly fossorial mode of life and clarifies early steps in the evolution of the shell. Sci Rep 2019; 9:10430. [PMID: 31320733 PMCID: PMC6639533 DOI: 10.1038/s41598-019-46762-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2019] [Accepted: 07/04/2019] [Indexed: 11/09/2022] Open
Abstract
Unlike any other tetrapod, turtles form their dorsal bony shell (carapace) not from osteoderms, but by contribution of the ribs and vertebrae that expand into the dermis to form plate-like shell components. Although this was known from embryological studies in extant turtles, important steps in this evolutionary sequence have recently been highlighted by the Triassic taxa Pappochelys, Eorhynchochelys and Odontochelys, and the Permian Eunotosaurus. The discovery of Pappochelys shed light on the origin of the ventral bony shell (plastron), which formed from enlarged gastralia. A major question is whether the turtle shell evolved in the context of a terrestrial or aquatic environment. Whereas Odontochelys was controversially interpreted as aquatic, a terrestrial origin of turtles was proposed based on evidence of fossorial adaptations in Eunotosaurus. We report palaeohistological data for Pappochelys, a taxon that exemplifies earlier evolutionary stages in the formation of the bony shell than Odontochelys. Bone histological evidence reveals (1) evolutionary changes in bone microstructure in ribs and gastralia approaching the turtle condition and (2) evidence for a predominantly amphibious or fossorial mode of life in Pappochelys, which support the hypothesis that crucial steps in the evolution of the shell occurred in a terrestrial rather than fully aquatic environment.
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Affiliation(s)
- Rainer R Schoch
- Staatliches Museum für Naturkunde Stuttgart, Rosenstein 1, D-70191, Stuttgart, Germany.
| | - Nicole Klein
- Staatliches Museum für Naturkunde Stuttgart, Rosenstein 1, D-70191, Stuttgart, Germany
- Institut für Geowissenschaften, Abteilung Paläontologie, Nussallee 8, 53115, Bonn, Germany
| | - Torsten M Scheyer
- Universität Zürich, Paläontologisches Institut und Museum, Karl-Schmid-Strasse 4, CH-8006, Zurich, Switzerland.
| | - Hans-Dieter Sues
- Department of Paleobiology, National Museum of Natural History, Smithsonian Institution, MRC 121, Washington, DC, 20560, USA
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17
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Ishikawa N, Hirayama Y, Miake Y, Kitamura K, Kasahara N, Abe S, Yamamoto H. Comparison of the Morphological Structures of the Human Calvarium and Turtle Shell. J HARD TISSUE BIOL 2019. [DOI: 10.2485/jhtb.28.289] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Affiliation(s)
- Noboru Ishikawa
- Department of Histology and Developmental Biology, Tokyo Dental College
| | - Yuzo Hirayama
- Department of Histology and Developmental Biology, Tokyo Dental College
| | - Yasuo Miake
- Department of Histology and Developmental Biology, Tokyo Dental College
| | - Kei Kitamura
- Department of Histology and Developmental Biology, Tokyo Dental College
| | - Norio Kasahara
- Department of Forensic Odontology and Anthropology, Tokyo Dental College
| | | | - Hitoshi Yamamoto
- Department of Histology and Developmental Biology, Tokyo Dental College
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18
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Evolution, Diversity, and Development of the Craniocervical System in Turtles with Special Reference to Jaw Musculature. HEADS, JAWS, AND MUSCLES 2019. [DOI: 10.1007/978-3-319-93560-7_8] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
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19
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Li C, Fraser NC, Rieppel O, Wu XC. A Triassic stem turtle with an edentulous beak. Nature 2018; 560:476-479. [DOI: 10.1038/s41586-018-0419-1] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/15/2018] [Indexed: 11/09/2022]
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20
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Achrai B, Wagner HD. The turtle carapace as an optimized multi-scale biological composite armor – A review. J Mech Behav Biomed Mater 2017; 73:50-67. [DOI: 10.1016/j.jmbbm.2017.02.027] [Citation(s) in RCA: 35] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2016] [Revised: 02/19/2017] [Accepted: 02/24/2017] [Indexed: 01/03/2023]
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21
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Moustakas-Verho JE, Cebra-Thomas J, Gilbert SF. Patterning of the turtle shell. Curr Opin Genet Dev 2017; 45:124-131. [DOI: 10.1016/j.gde.2017.03.016] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2016] [Revised: 03/06/2017] [Accepted: 03/21/2017] [Indexed: 12/30/2022]
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22
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Joyce WG. A Review of the Fossil Record of Basal Mesozoic Turtles. BULLETIN OF THE PEABODY MUSEUM OF NATURAL HISTORY 2017. [DOI: 10.3374/014.058.0105] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Walter G. Joyce
- Department of Geosciences, University of Fribourg, 1700 Fribourg, Switzerland—
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23
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Szczygielski T. Homeotic shift at the dawn of the turtle evolution. ROYAL SOCIETY OPEN SCIENCE 2017; 4:160933. [PMID: 28484613 PMCID: PMC5414250 DOI: 10.1098/rsos.160933] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/21/2016] [Accepted: 03/08/2017] [Indexed: 06/07/2023]
Abstract
All derived turtles are characterized by one of the strongest reductions of the dorsal elements among Amniota, and have only 10 dorsal and eight cervical vertebrae. I demonstrate that the Late Triassic turtles, which represent successive stages of the shell evolution, indicate that the shift of the boundary between the cervical and dorsal sections of the vertebral column occurred over the course of several million years after the formation of complete carapace. The more generalized reptilian formula of at most seven cervicals and at least 11 dorsals is thus plesiomorphic for Testudinata. The morphological modifications associated with an anterior homeotic change of the first dorsal vertebra towards the last cervical vertebra in the Triassic turtles are partially recapitulated by the reduction of the first dorsal vertebra in crown-group Testudines, and they resemble the morphologies observed under laboratory conditions resulting from the experimental changes of Hox gene expression patterns. This homeotic shift hypothesis is supported by the, unique to turtles, restriction of Hox-5 expression domains, somitic precursors of scapula, and brachial plexus branches to the cervical region, by the number of the marginal scute-forming placodes, which was larger in the Triassic than in modern turtles, and by phylogenetic analyses.
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24
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Canoville A, Chinsamy A. Bone Microstructure of Pareiasaurs (Parareptilia) from the Karoo Basin, South Africa: Implications for Growth Strategies and Lifestyle Habits. Anat Rec (Hoboken) 2017; 300:1039-1066. [PMID: 27997077 DOI: 10.1002/ar.23534] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2016] [Revised: 10/14/2016] [Accepted: 10/21/2016] [Indexed: 11/10/2022]
Abstract
Numerous morphological studies have been carried out on pareiasaurs; yet their taxonomy and biology remain incompletely understood. Earlier works have suggested that these herbivorous parareptiles had a short juvenile period as compared to the duration of adulthood. Several studies further suggested an (semi-) aquatic lifestyle for these animals, but more recent investigations have proposed a rather terrestrial habitat. Bone paleohistology is regarded as a powerful tool to assess aspects of tetrapod paleobiology, but few studies have been conducted on pareiasaurs. The present study assesses intra and inter-specific histovariability of pareiasaurs and provides fresh insights into their paleobiology, thereby permitting a re-evaluation of earlier hypotheses. Our sample comprises various skeletal elements and several specimens covering most of the taxonomic and stratigraphic spectrum of South African pareiasaurs, including large and basal forms from the Middle Permian, as well as smaller and more derived forms from the Late Permian. Our results concerning size of elements and histological tissues show that for pareiasaurs, element size is not a good indicator of ontogenetic age, and furthermore, suggest that the specific diversity of the Middle Permian pareiasaurs may have been underestimated. The bone histology of these animals shows that they experienced a relatively rapid growth early in ontogeny. Periosteal growth later slowed down, but seems to have been protracted for several years during adulthood. Pareiasaur bone microanatomy is unusual for continental tetrapods, in having spongious stylopod diaphyses and thin compact cortices. Rigorous paleoecological interpretations are thus limited since no modern analogue exists for these animals. Anat Rec, 300:1039-1066, 2017. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Aurore Canoville
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
| | - Anusuya Chinsamy
- Department of Biological Sciences, University of Cape Town, Private Bag X3, Rondebosch, 7701, South Africa
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25
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Foth C, Rabi M, Joyce WG. Skull shape variation in extant and extinct Testudinata and its relation to habitat and feeding ecology. ACTA ZOOL-STOCKHOLM 2016. [DOI: 10.1111/azo.12181] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
Affiliation(s)
- Christian Foth
- Departement für Geowissenschaften; Universität Freiburg; 1700 Freiburg Switzerland
| | - Márton Rabi
- Department of Earth Sciences; University of Turin; 10125 Turin Italy
- Institut für Geowissenschaften; Universität Tübingen; 72074 Tübingen Germany
| | - Walter G. Joyce
- Departement für Geowissenschaften; Universität Freiburg; 1700 Freiburg Switzerland
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26
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Bever G, Lyson TR, Field DJ, Bhullar BAS. The amniote temporal roof and the diapsid origin of the turtle skull. ZOOLOGY 2016; 119:471-473. [DOI: 10.1016/j.zool.2016.04.005] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2016] [Revised: 04/22/2016] [Accepted: 04/26/2016] [Indexed: 12/01/2022]
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27
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Lambertz M, Shelton CD, Spindler F, Perry SF. A caseian point for the evolution of a diaphragm homologue among the earliest synapsids. Ann N Y Acad Sci 2016; 1385:3-20. [PMID: 27859325 DOI: 10.1111/nyas.13264] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 08/07/2016] [Accepted: 09/01/2016] [Indexed: 01/14/2023]
Abstract
The origin of the diaphragm remains a poorly understood yet crucial step in the evolution of terrestrial vertebrates, as this unique structure serves as the main respiratory motor for mammals. Here, we analyze the paleobiology and the respiratory apparatus of one of the oldest lineages of mammal-like reptiles: the Caseidae. Combining quantitative bone histology and functional morphological and physiological modeling approaches, we deduce a scenario in which an auxiliary ventilatory structure was present in these early synapsids. Crucial to this hypothesis are indications that at least the phylogenetically advanced caseids might not have been primarily terrestrial but rather were bound to a predominantly aquatic life. Such a lifestyle would have resulted in severe constraints on their ventilatory system, which consequently would have had to cope with diving-related problems. Our modeling of breathing parameters revealed that these caseids were capable of only limited costal breathing and, if aquatic, must have employed some auxiliary ventilatory mechanism to quickly meet their oxygen demand upon surfacing. Given caseids' phylogenetic position at the base of Synapsida and under this aquatic scenario, it would be most parsimonious to assume that a homologue of the mammalian diaphragm had already evolved about 50 Ma earlier than previously assumed.
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Affiliation(s)
- Markus Lambertz
- Institut für Zoologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.,Sektion Herpetologie, Zoologisches Forschungsmuseum Alexander Koenig, Bonn, Germany
| | - Christen D Shelton
- Steinmann-Institut für Geologie, Mineralogie und Paläontologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany.,Palaeobiology Research Group, Department of Biological Sciences, University of Cape Town, Rhodes Gift, South Africa
| | - Frederik Spindler
- Institut für Geologie, Technische Universität Bergakademie Freiberg, Freiberg, Germany.,Dinosaurier-Park Altmühltal, Denkendorf, Germany
| | - Steven F Perry
- Institut für Zoologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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28
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Lambertz M. Recent advances on the functional and evolutionary morphology of the amniote respiratory apparatus. Ann N Y Acad Sci 2016; 1365:100-13. [PMID: 27037667 DOI: 10.1111/nyas.13022] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2015] [Revised: 01/14/2016] [Accepted: 01/19/2016] [Indexed: 12/30/2022]
Abstract
Increased organismic complexity in metazoans was achieved via the specialization of certain parts of the body involved in different faculties (structure-function complexes). One of the most basic metabolic demands of animals in general is a sufficient supply of all tissues with oxygen. Specialized structures for gas exchange (and transport) consequently evolved many times and in great variety among bilaterians. This review focuses on some of the latest advancements that morphological research has added to our understanding of how the respiratory apparatus of the primarily terrestrial vertebrates (amniotes) works and how it evolved. Two main components of the respiratory apparatus, the lungs as the "exchanger" and the ventilatory apparatus as the "active pump," are the focus of this paper. Specific questions related to the exchanger concern the structure of the lungs of the first amniotes and the efficiency of structurally simple snake lungs in health and disease, as well as secondary functions of the lungs in heat exchange during the evolution of sauropod dinosaurs. With regard to the active pump, I discuss how the unique ventilatory mechanism of turtles evolved and how understanding the avian ventilatory strategy affects animal welfare issues in the poultry industry.
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Affiliation(s)
- Markus Lambertz
- Institut für Zoologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Bonn, Germany
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29
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Lyson T, Rubidge B, Scheyer T, de Queiroz K, Schachner E, Smith R, Botha-Brink J, Bever G. Fossorial Origin of the Turtle Shell. Curr Biol 2016; 26:1887-94. [DOI: 10.1016/j.cub.2016.05.020] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2016] [Revised: 05/03/2016] [Accepted: 05/05/2016] [Indexed: 10/21/2022]
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30
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Schoch RR, Sues HD. The diapsid origin of turtles. ZOOLOGY 2016; 119:159-161. [DOI: 10.1016/j.zool.2016.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2016] [Accepted: 01/25/2016] [Indexed: 10/22/2022]
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31
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Szczygielski T, Sulej T. Revision of the Triassic European turtlesProterochersisandMurrhardtia(Reptilia, Testudinata, Proterochersidae), with the description of new taxa from Poland and Germany. Zool J Linn Soc 2016. [DOI: 10.1111/zoj.12374] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Tomasz Szczygielski
- Institute of Palaeobiology; Polish Academy of Sciences; Twarda 51/55 00-818 Warsaw Poland
| | - Tomasz Sulej
- Institute of Palaeobiology; Polish Academy of Sciences; Twarda 51/55 00-818 Warsaw Poland
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32
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Development of the turtle plastron, the order-defining skeletal structure. Proc Natl Acad Sci U S A 2016; 113:5317-22. [PMID: 27114549 DOI: 10.1073/pnas.1600958113] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022] Open
Abstract
The dorsal and ventral aspects of the turtle shell, the carapace and the plastron, are developmentally different entities. The carapace contains axial endochondral skeletal elements and exoskeletal dermal bones. The exoskeletal plastron is found in all extant and extinct species of crown turtles found to date and is synaptomorphic of the order Testudines. However, paleontological reconstructed transition forms lack a fully developed carapace and show a progression of bony elements ancestral to the plastron. To understand the evolutionary development of the plastron, it is essential to know how it has formed. Here we studied the molecular development and patterning of plastron bones in a cryptodire turtle Trachemys scripta We show that plastron development begins at developmental stage 15 when osteochondrogenic mesenchyme forms condensates for each plastron bone at the lateral edges of the ventral mesenchyme. These condensations commit to an osteogenic identity and suppress chondrogenesis. Their development overlaps with that of sternal cartilage development in chicks and mice. Thus, we suggest that in turtles, the sternal morphogenesis is prevented in the ventral mesenchyme by the concomitant induction of osteogenesis and the suppression of chondrogenesis. The osteogenic subroutines later direct the growth and patterning of plastron bones in an autonomous manner. The initiation of plastron bone development coincides with that of carapacial ridge formation, suggesting that the development of dorsal and ventral shells are coordinated from the start and that adopting an osteogenesis-inducing and chondrogenesis-suppressing cell fate in the ventral mesenchyme has permitted turtles to develop their order-specific ventral morphology.
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Moustakas-Verho JE, Cherepanov GO. The integumental appendages of the turtle shell: an evo-devo perspective. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2016; 324:221-9. [PMID: 25877335 DOI: 10.1002/jez.b.22619] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/18/2014] [Accepted: 02/26/2015] [Indexed: 12/24/2022]
Abstract
The turtle shell is composed of dorsal armor (carapace) and ventral armor (plastron) covered by a keratinized epithelium. There are two epithelial appendages of the turtle shell: scutes (large epidermal shields separated by furrows and forming a unique mosaic) and tubercles (numerous small epidermal bumps located on the carapaces of some species). In our perspective, we take a synthetic, comparative approach to consider the homology and evolution of these integumental appendages. Scutes have been more intensively studied, as they are autapomorphic for turtles and can be diagnostic taxonomically. Their pattern of tessellation is stable phylogenetically, but labile in the individual. We discuss the history of developmental investigations of these structures and hypotheses of evolutionary and anomalous variation. In our estimation, the scutes of the turtle shell are an evolutionary novelty, whereas the tubercles found on the shells of some turtles are homologous to reptilian scales.
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Canoville A, de Buffrénil V, Laurin M. Microanatomical diversity of amniote ribs: an exploratory quantitative study. Biol J Linn Soc Lond 2016. [DOI: 10.1111/bij.12779] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Affiliation(s)
- Aurore Canoville
- Bonn University; Steinmann Institute for Geology; Mineralogy and Paleontology; Nußallee 8 53115 Bonn Germany
| | - Vivian de Buffrénil
- CR2P; Centre de Recherches sur la Paléobiodiversité et les Paléoenvironnements; Sorbonne Universités; CNRS/MNHN/UPMC; Muséum National d'Histoire Naturelle; Bâtiment de Géologie; Case postale 48, 43 rue Buffon, F-75231 Paris Cedex 05 Paris France
| | - Michel Laurin
- CR2P; Centre de Recherches sur la Paléobiodiversité et les Paléoenvironnements; Sorbonne Universités; CNRS/MNHN/UPMC; Muséum National d'Histoire Naturelle; Bâtiment de Géologie; Case postale 48, 43 rue Buffon, F-75231 Paris Cedex 05 Paris France
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Cordero GA, Quinteros K. Skeletal remodelling suggests the turtle's shell is not an evolutionary straitjacket. Biol Lett 2016; 11:20150022. [PMID: 25878046 DOI: 10.1098/rsbl.2015.0022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Recent efforts to decipher the enigma of the turtle's shell revealed that distantly related turtle species deploy diverse processes during shell development. Even so, extant species share in common a shoulder blade (scapula) that is encapsulated within the shell. Thus, evolutionary change in the correlated development of the shell and scapula probably underpins the evolution of highly derived shell morphologies. To address this expectation, we conducted one of the most phylogenetically comprehensive surveys of turtle development, focusing on scapula growth and differentiation in embryos, hatchlings and adults of 13 species. We report, to our knowledge, the first description of secondary differentiation owing to skeletal remodelling of the tetrapod scapula in turtles with the most structurally derived shell phenotypes. Remodelling and secondary differentiation late in embryogenesis of box turtles (Emys and Terrapene) yielded a novel skeletal segment (i.e. the suprascapula) of high functional value to their complex shell-closing system. Remarkably, our analyses suggest that, in soft-shelled turtles (Trionychidae) with extremely flattened shells, a similar transformation is linked to truncated scapula growth. Skeletal remodelling, as a form of developmental plasticity, might enable the seemingly constrained turtle body plan to diversify, suggesting the shell is not an evolutionary straitjacket.
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Affiliation(s)
- Gerardo Antonio Cordero
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA 50011, USA
| | - Kevin Quinteros
- Department of Ecology, Evolution, and Organismal Biology, Iowa State University, 251 Bessey Hall, Ames, IA 50011, USA
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Abstract
Transitional fossils informing the origin of turtles are among the most sought-after discoveries in palaeontology. Despite strong genomic evidence indicating that turtles evolved from within the diapsid radiation (which includes all other living reptiles), evidence of the inferred transformation between an ancestral turtle with an open, diapsid skull to the closed, anapsid condition of modern turtles remains elusive. Here we use high-resolution computed tomography and a novel character/taxon matrix to study the skull of Eunotosaurus africanus, a 260-million-year-old fossil reptile from the Karoo Basin of South Africa, whose distinctive postcranial skeleton shares many unique features with the shelled body plan of turtles. Scepticism regarding the status of Eunotosaurus as the earliest stem turtle arises from the possibility that these shell-related features are the products of evolutionary convergence. Our phylogenetic analyses indicate strong cranial support for Eunotosaurus as a critical transitional form in turtle evolution, thus fortifying a 40-million-year extension to the turtle stem and moving the ecological context of its origin back onto land. Furthermore, we find unexpected evidence that Eunotosaurus is a diapsid reptile in the process of becoming secondarily anapsid. This is important because categorizing the skull based on the number of openings in the complex of dermal bone covering the adductor chamber has long held sway in amniote systematics, and still represents a common organizational scheme for teaching the evolutionary history of the group. These discoveries allow us to articulate a detailed and testable hypothesis of fenestral closure along the turtle stem. Our results suggest that Eunotosaurus represents a crucially important link in a chain that will eventually lead to consilience in reptile systematics, paving the way for synthetic studies of amniote evolution and development.
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Moczek AP, Sears KE, Stollewerk A, Wittkopp PJ, Diggle P, Dworkin I, Ledon-Rettig C, Matus DQ, Roth S, Abouheif E, Brown FD, Chiu CH, Cohen CS, Tomaso AWD, Gilbert SF, Hall B, Love AC, Lyons DC, Sanger TJ, Smith J, Specht C, Vallejo-Marin M, Extavour CG. The significance and scope of evolutionary developmental biology: a vision for the 21st century. Evol Dev 2015; 17:198-219. [PMID: 25963198 DOI: 10.1111/ede.12125] [Citation(s) in RCA: 55] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Evolutionary developmental biology (evo-devo) has undergone dramatic transformations since its emergence as a distinct discipline. This paper aims to highlight the scope, power, and future promise of evo-devo to transform and unify diverse aspects of biology. We articulate key questions at the core of eleven biological disciplines-from Evolution, Development, Paleontology, and Neurobiology to Cellular and Molecular Biology, Quantitative Genetics, Human Diseases, Ecology, Agriculture and Science Education, and lastly, Evolutionary Developmental Biology itself-and discuss why evo-devo is uniquely situated to substantially improve our ability to find meaningful answers to these fundamental questions. We posit that the tools, concepts, and ways of thinking developed by evo-devo have profound potential to advance, integrate, and unify biological sciences as well as inform policy decisions and illuminate science education. We look to the next generation of evolutionary developmental biologists to help shape this process as we confront the scientific challenges of the 21st century.
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Affiliation(s)
- Armin P Moczek
- Department of Biology, Indiana University, 915 East 3rd Street, Bloomington, IN 47405, USA
| | - Karen E Sears
- School of Integrative Biology and Institute for Genomic Biology, University of Illinois, 505 South Goodwin Avenue, Urbana, IL, 61801, USA
| | - Angelika Stollewerk
- School of Biological and Chemical Sciences, Queen Mary, University of London, Mile End Road, London, E1 4NS, UK
| | - Patricia J Wittkopp
- Department of Ecology and Evolutionary Biology, Department of Molecular, Cellular, and Developmental Biology, University of Michigan, Ann Arbor, MI, USA
| | - Pamela Diggle
- Department of Ecology and Evolutionary Biology, University of Connecticut, Storrs, CT, 06269, USA
| | - Ian Dworkin
- Department of Biology, McMaster University, 1280 Main St. West Hamilton, Ontario, L8S 4K1, Canada
| | - Cristina Ledon-Rettig
- Department of Biology, Indiana University, 915 East 3rd Street, Bloomington, IN 47405, USA
| | - David Q Matus
- Department of Biochemistry and Cell Biology, Stony Brook University, 412 Life Sciences Building, Stony Brook, NY, 11794-5215, USA
| | - Siegfried Roth
- University of Cologne, Institute of Developmental Biology, Biocenter, Zülpicher Straße 47b, D-50674, Cologne, Germany
| | - Ehab Abouheif
- Department of Biology, McGill University, 1205 Avenue Docteur Penfield, Montréal Québec, H3A 1B1, Canada
| | - Federico D Brown
- Departamento de Zoologia, Instituto Biociências, Universidade de São Paulo, Rua do Matão, Travessa 14, no. 101, 05508-090, São Paulo, Brazil
| | - Chi-Hua Chiu
- Department of Biological Sciences, Kent State University, OH, USA
| | - C Sarah Cohen
- Biology Department, Romberg Tiburon Center for Environmental Studies, San Francisco State University, 3150 Paradise Drive, Tiburon, CA, 94920, USA
| | | | - Scott F Gilbert
- Department of Biology, Swarthmore College, Swarthmore, Pennsylvania 19081, USA and Biotechnology Institute, University of Helsinki, 00014, Helsinki, Finland
| | - Brian Hall
- Department of Biology, Dalhousie University, Halifax, Nova Scotia, CA, B3H 4R2, USA
| | - Alan C Love
- Department of Philosophy, Minnesota Center for Philosophy of Science, University of Minnesota, USA
| | - Deirdre C Lyons
- Department of Biology, Duke University, Box 90338, Durham, NC, 27708, USA
| | - Thomas J Sanger
- Department of Molecular Genetics and Microbiology, University of Florida, P.O. Box 103610, Gainesville, FL, 32610, USA
| | - Joel Smith
- Marine Biological Laboratory, 7 MBL Street, Woods Hole, MA, 02543, USA
| | - Chelsea Specht
- Plant and Microbial Biology, Department of Integrative Biology, University and Jepson Herbaria, University of California, Berkeley, CA, USA
| | - Mario Vallejo-Marin
- Biological and Environmental Sciences, University of Stirling, FK9 4LA, Scotland, UK
| | - Cassandra G Extavour
- Department of Organismic and Evolutionary Biology, Department of Molecular and Cellular Biology, Harvard University, 16 Divinity Avenue, BioLabs 4103, Cambridge, MA, 02138, USA
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Vlachos E, Cerda I, Tsoukala E. The first record of a soft-shelled turtle (Testudines: Pan-Trionychidae) from southern Balkans (Pliocene, Gefira, N. Greece) and new information from bone histology. Naturwissenschaften 2015; 102:45. [PMID: 26231846 DOI: 10.1007/s00114-015-1295-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2015] [Revised: 07/06/2015] [Accepted: 07/09/2015] [Indexed: 10/23/2022]
Abstract
Soft-shelled turtles (Pan-Trionychidae) are not included in the present-day chelonian fauna of Greece and have been unknown in the Greek fossil record up to now. Here, we report the first fossil occurrence of a soft-shelled turtle from Greece, originating from the Pliocene Gefira Member (Angelochori Formation), in the lower Axios valley. The corresponding specimens were discovered with several mammalian remains, most of them attributable to the mastodon of Auvergne, Anancus arvernensis. The chelonian material includes five carapacial fragments that belong to the same individual and can be attributed to Pan-Trionychidae based on the typical sculpturing on the dorsal side of the carapace. Most of these bony plates were histologically sampled and thereby provide evidence for the "plywood" structure, another characteristic of pan-trionychids. They represent the first extended sampling of trionychid plates that belong to the same individual, allowing the documentation of the variation of the relevant trionychid morphologies in the carapace. These findings expand the paleobiogeographic range of this taxon to the southern Balkans and Greece and allow a better estimation of the chelonian paleo-fauna of the area. They are also important for the temporal distribution of this clade in the Paleoarctic, as they join specimens from Italy as being the last trionychids in Europe.
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Affiliation(s)
- Evangelos Vlachos
- CONICET and Museo Paleontológico Egidio Feruglio, Av. Fontana 140, 9100, Trelew, Chubut, Argentina,
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Hill RV, D'Emic MD, Bever GS, Norell MA. A complex hyobranchial apparatus in a Cretaceous dinosaur and the antiquity of avian paraglossalia. Zool J Linn Soc 2015. [DOI: 10.1111/zoj.12293] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Affiliation(s)
- Robert V. Hill
- Department of Anatomy; New York Institute of Technology College of Osteopathic Medicine; Northern Boulevard Old Westbury NY 11568-8000 USA
| | - Michael D. D'Emic
- Department of Anatomical Sciences; Stony Brook University; HSC-T8, Room 040 Stony Brook NY 11794-8081 USA
| | - G. S. Bever
- Department of Anatomy; New York Institute of Technology College of Osteopathic Medicine; Northern Boulevard Old Westbury NY 11568-8000 USA
- Division of Paleontology; American Museum of Natural History; New York NY 10024 USA
| | - Mark A. Norell
- Division of Paleontology; American Museum of Natural History; New York NY 10024 USA
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40
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Schoch RR, Sues HD. A Middle Triassic stem-turtle and the evolution of the turtle body plan. Nature 2015; 523:584-7. [DOI: 10.1038/nature14472] [Citation(s) in RCA: 105] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2015] [Accepted: 04/13/2015] [Indexed: 01/10/2023]
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41
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Joyce WG. The origin of turtles: a paleontological perspective. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2015; 324:181-93. [PMID: 25712176 DOI: 10.1002/jez.b.22609] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2014] [Accepted: 10/27/2014] [Indexed: 11/10/2022]
Abstract
The origin of turtles and their unusual body plan has fascinated scientists for the last two centuries. Over the course of the last decades, a broad sample of molecular analyses have favored a sister group relationship of turtles with archosaurs, but recent studies reveal that this signal may be the result of systematic biases affecting molecular approaches, in particular sampling, non-randomly distributed rate heterogeneity among taxa, and the use of concatenated data sets. Morphological studies, by contrast, disfavor archosaurian relationships for turtles, but the proposed alternative topologies are poorly supported as well. The recently revived paleontological hypothesis that the Middle Permian Eunotosaurus africanus is an intermediate stem turtle is now robustly supported by numerous characters that were previously thought to be unique to turtles and that are now shown to have originated over the course of tens of millions of years unrelated to the origin of the turtle shell. Although E. africanus does not solve the placement of turtles within Amniota, it successfully extends the stem lineage of turtles to the Permian and helps resolve some questions associated with the origin of turtles, in particular the non-composite origin of the shell, the slow origin of the shell, and the terrestrial setting for the origin of turtles.
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Affiliation(s)
- Walter G Joyce
- Department of Geoscience, University of Fribourg, Fribourg, Switzerland
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42
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Achrai B, Bar-On B, Wagner HD. Biological armors under impact--effect of keratin coating, and synthetic bio-inspired analogues. BIOINSPIRATION & BIOMIMETICS 2015; 10:016009. [PMID: 25599251 DOI: 10.1088/1748-3190/10/1/016009] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
A number of biological armors, such as turtle shells, consist of a strong exoskeleton covered with a thin keratin coating. The mechanical role upon impact of this keratin coating has surprisingly not been investigated thus far. Low-velocity impact tests on the turtle shell reveal a unique toughening phenomenon attributed to the thin covering keratin layer, the presence of which noticeably improves the fracture energy and shell integrity. Synthetic substrate/coating analogues were subsequently prepared and exhibit an impact behavior similar to the biological ones. The results of the present study may improve our understanding, and even future designs, of impact-tolerant structures.
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Affiliation(s)
- B Achrai
- Department of Materials and Interfaces, Weizmann Institute of Science, Rehovot 76100, Israel
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Green RE, Braun EL, Armstrong J, Earl D, Nguyen N, Hickey G, Vandewege MW, St John JA, Capella-Gutiérrez S, Castoe TA, Kern C, Fujita MK, Opazo JC, Jurka J, Kojima KK, Caballero J, Hubley RM, Smit AF, Platt RN, Lavoie CA, Ramakodi MP, Finger JW, Suh A, Isberg SR, Miles L, Chong AY, Jaratlerdsiri W, Gongora J, Moran C, Iriarte A, McCormack J, Burgess SC, Edwards SV, Lyons E, Williams C, Breen M, Howard JT, Gresham CR, Peterson DG, Schmitz J, Pollock DD, Haussler D, Triplett EW, Zhang G, Irie N, Jarvis ED, Brochu CA, Schmidt CJ, McCarthy FM, Faircloth BC, Hoffmann FG, Glenn TC, Gabaldón T, Paten B, Ray DA. Three crocodilian genomes reveal ancestral patterns of evolution among archosaurs. Science 2014; 346:1254449. [PMID: 25504731 PMCID: PMC4386873 DOI: 10.1126/science.1254449] [Citation(s) in RCA: 230] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
To provide context for the diversification of archosaurs--the group that includes crocodilians, dinosaurs, and birds--we generated draft genomes of three crocodilians: Alligator mississippiensis (the American alligator), Crocodylus porosus (the saltwater crocodile), and Gavialis gangeticus (the Indian gharial). We observed an exceptionally slow rate of genome evolution within crocodilians at all levels, including nucleotide substitutions, indels, transposable element content and movement, gene family evolution, and chromosomal synteny. When placed within the context of related taxa including birds and turtles, this suggests that the common ancestor of all of these taxa also exhibited slow genome evolution and that the comparatively rapid evolution is derived in birds. The data also provided the opportunity to analyze heterozygosity in crocodilians, which indicates a likely reduction in population size for all three taxa through the Pleistocene. Finally, these data combined with newly published bird genomes allowed us to reconstruct the partial genome of the common ancestor of archosaurs, thereby providing a tool to investigate the genetic starting material of crocodilians, birds, and dinosaurs.
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Affiliation(s)
- Richard E Green
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA.
| | - Edward L Braun
- Department of Biology and Genetics Institute, University of Florida, Gainesville, FL 32611, USA
| | - Joel Armstrong
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Dent Earl
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Ngan Nguyen
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Glenn Hickey
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA. Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Michael W Vandewege
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA
| | - John A St John
- Department of Biomolecular Engineering, University of California, Santa Cruz, CA 95064, USA
| | - Salvador Capella-Gutiérrez
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain. Universitat Pompeu Fabra, 08003 Barcelona, Spain
| | - Todd A Castoe
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA. Department of Biology, University of Texas, Arlington, TX 76019, USA
| | - Colin Kern
- Department of Computer and Information Sciences, University of Delaware, Newark, DE 19717, USA
| | - Matthew K Fujita
- Department of Biology, University of Texas, Arlington, TX 76019, USA
| | - Juan C Opazo
- Instituto de Ciencias Ambientales y Evolutivas, Facultad de Ciencias, Universidad Austral de Chile, Valdivia, Chile
| | - Jerzy Jurka
- Genetic Information Research Institute, Mountain View, CA 94043, USA
| | - Kenji K Kojima
- Genetic Information Research Institute, Mountain View, CA 94043, USA
| | | | | | - Arian F Smit
- Institute for Systems Biology, Seattle, WA 98109, USA
| | - Roy N Platt
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Christine A Lavoie
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Meganathan P Ramakodi
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - John W Finger
- Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Alexander Suh
- Institute of Experimental Pathology (ZMBE), University of Münster, D-48149 Münster, Germany. Department of Evolutionary Biology (EBC), Uppsala University, SE-752 36 Uppsala, Sweden
| | - Sally R Isberg
- Porosus Pty. Ltd., Palmerston, NT 0831, Australia. Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia. Centre for Crocodile Research, Noonamah, NT 0837, Australia
| | - Lee Miles
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Amanda Y Chong
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | | | - Jaime Gongora
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Christopher Moran
- Faculty of Veterinary Science, University of Sydney, Sydney, NSW 2006, Australia
| | - Andrés Iriarte
- Departamento de Desarrollo Biotecnológico, Instituto de Higiene, Facultad de Medicina, Universidad de la República, Montevideo, Uruguay
| | - John McCormack
- Moore Laboratory of Zoology, Occidental College, Los Angeles, CA 90041, USA
| | - Shane C Burgess
- College of Agriculture and Life Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Scott V Edwards
- Department of Organismic and Evolutionary Biology, Harvard University, Cambridge, MA 02138, USA
| | - Eric Lyons
- School of Plant Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Christina Williams
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607, USA
| | - Matthew Breen
- Department of Molecular Biomedical Sciences, North Carolina State University, Raleigh, NC 27607, USA
| | - Jason T Howard
- Howard Hughes Medical Institute, Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Cathy R Gresham
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Daniel G Peterson
- Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA. Department of Plant and Soil Sciences, Mississippi State University, Mississippi State, MS 39762, USA
| | - Jürgen Schmitz
- Institute of Experimental Pathology (ZMBE), University of Münster, D-48149 Münster, Germany
| | - David D Pollock
- Department of Biochemistry and Molecular Genetics, University of Colorado School of Medicine, Aurora, CO 80045, USA
| | - David Haussler
- Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA. Howard Hughes Medical Institute, Bethesda, MD 20814, USA
| | - Eric W Triplett
- Department of Microbiology and Cell Science, University of Florida, Gainesville, FL 32611, USA
| | - Guojie Zhang
- China National GeneBank, BGI-Shenzhen, Shenzhen, China. Center for Social Evolution, Department of Biology, University of Copenhagen, Copenhagen, Denmark
| | - Naoki Irie
- Department of Biological Sciences, Graduate School of Science, University of Tokyo, Tokyo, Japan
| | - Erich D Jarvis
- Howard Hughes Medical Institute, Department of Neurobiology, Duke University Medical Center, Durham, NC 27710, USA
| | - Christopher A Brochu
- Department of Earth and Environmental Sciences, University of Iowa, Iowa City, IA 52242, USA
| | - Carl J Schmidt
- Department of Animal and Food Sciences, University of Delaware, Newark, DE 19717, USA
| | - Fiona M McCarthy
- School of Animal and Comparative Biomedical Sciences, University of Arizona, Tucson, AZ 85721, USA
| | - Brant C Faircloth
- Department of Ecology and Evolutionary Biology, University of California, Los Angeles, CA 90019, USA. Department of Biological Sciences, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Federico G Hoffmann
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA
| | - Travis C Glenn
- Department of Environmental Health Science, University of Georgia, Athens, GA 30602, USA
| | - Toni Gabaldón
- Bioinformatics and Genomics Programme, Centre for Genomic Regulation, 08003 Barcelona, Spain. Universitat Pompeu Fabra, 08003 Barcelona, Spain. Institució Catalana de Recerca i Estudis Avançats, 08010 Barcelona, Spain
| | - Benedict Paten
- Center for Biomolecular Science and Engineering, University of California, Santa Cruz, CA 95064, USA
| | - David A Ray
- Department of Biochemistry, Molecular Biology, Entomology and Plant Pathology, Mississippi State University, Mississippi State, MS 39762, USA. Institute for Genomics, Biocomputing and Biotechnology, Mississippi State University, Mississippi State, MS 39762, USA. Department of Biological Sciences, Texas Tech University, Lubbock, TX 79409, USA.
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Lyson TR, Schachner ER, Botha-Brink J, Scheyer TM, Lambertz M, Bever GS, Rubidge BS, de Queiroz K. Origin of the unique ventilatory apparatus of turtles. Nat Commun 2014; 5:5211. [PMID: 25376734 DOI: 10.1038/ncomms6211] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2014] [Accepted: 09/10/2014] [Indexed: 11/09/2022] Open
Abstract
The turtle body plan differs markedly from that of other vertebrates and serves as a model system for studying structural and developmental evolution. Incorporation of the ribs into the turtle shell negates the costal movements that effect lung ventilation in other air-breathing amniotes. Instead, turtles have a unique abdominal-muscle-based ventilatory apparatus whose evolutionary origins have remained mysterious. Here we show through broadly comparative anatomical and histological analyses that an early member of the turtle stem lineage has several turtle-specific ventilation characters: rigid ribcage, inferred loss of intercostal muscles and osteological correlates of the primary expiratory muscle. Our results suggest that the ventilation mechanism of turtles evolved through a division of labour between the ribs and muscles of the trunk in which the abdominal muscles took on the primary ventilatory function, whereas the broadened ribs became the primary means of stabilizing the trunk. These changes occurred approximately 50 million years before the evolution of the fully ossified shell.
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Affiliation(s)
- Tyler R Lyson
- 1] Department of Earth Sciences, Denver Museum of Nature and Science, Denver, Colorado 80205, USA [2] Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington DC 20560, USA [3] Evolutionary Studies Institute, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa
| | - Emma R Schachner
- 1] Department of Veterinary Clinical Sciences, School of Veterinary Medicine, Louisiana State University, Baton Rouge, Louisiana 70803, USA [2] Department of Biology, University of Utah, Salt Lake City, Utah 84112, USA
| | - Jennifer Botha-Brink
- 1] Karoo Palaeontology, National Museum, Box 266, Bloemfontein 9300, South Africa [2] Department of Zoology and Entomology, University of the Free State, Bloemfontein 9300, South Africa
| | - Torsten M Scheyer
- Paläontologisches Institut und Museum, Universität Zürich, Karl Schmid-Strasse 4, 8006 Zürich, Switzerland
| | - Markus Lambertz
- Institut für Zoologie, Rheinische Friedrich-Wilhelms-Universität Bonn, Poppelsdorfer Schloss, 53115 Bonn, Germany
| | - G S Bever
- 1] Evolutionary Studies Institute, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa [2] New York Institute of Technology, College of Osteopathic Medicine, Old Westbury, New York 11568, USA [3] Division of Paleontology, American Museum of Natural History, New York, New York 10024, USA
| | - Bruce S Rubidge
- Evolutionary Studies Institute, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa
| | - Kevin de Queiroz
- Department of Vertebrate Zoology, National Museum of Natural History, Smithsonian Institution, Washington DC 20560, USA
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MacCord K, Caniglia G, Moustakas-Verho JE, Burke AC. The dawn of chelonian research: Turtles between comparative anatomy and embryology in the 19th century. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 324:169-80. [DOI: 10.1002/jez.b.22587] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/21/2014] [Accepted: 06/18/2014] [Indexed: 11/10/2022]
Affiliation(s)
- Kate MacCord
- Center for Biology and Society; Arizona State University; Tempe Arizona
| | - Guido Caniglia
- Center for Biology and Society; Arizona State University; Tempe Arizona
| | | | - Ann C. Burke
- Department of Biology; Wesleyan University; Middletown Connecticut
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Nakajima Y, Hirayama R, Endo H. Turtle humeral microanatomy and its relationship to lifestyle. Biol J Linn Soc Lond 2014. [DOI: 10.1111/bij.12336] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Affiliation(s)
- Yasuhisa Nakajima
- Steinmann Institute for Geology, Mineralogy and Paleontology; University of Bonn; Nussallee 8 53115 Bonn Germany
| | - Ren Hirayama
- School of International Liberal Studies; Waseda University; Nishiwaseda 1-6-1 Shinjuku-ku Tokyo Japan
| | - Hideki Endo
- The University Museum; The University of Tokyo; 7-3-1 Hongo Bunkyo-ku Tokyo Japan
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Field DJ, Gauthier JA, King BL, Pisani D, Lyson TR, Peterson KJ. Toward consilience in reptile phylogeny: miRNAs support an archosaur, not lepidosaur, affinity for turtles. Evol Dev 2014; 16:189-96. [PMID: 24798503 PMCID: PMC4215941 DOI: 10.1111/ede.12081] [Citation(s) in RCA: 74] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
Understanding the phylogenetic position of crown turtles (Testudines) among amniotes has been a source of particular contention. Recent morphological analyses suggest that turtles are sister to all other reptiles, whereas the vast majority of gene sequence analyses support turtles as being inside Diapsida, and usually as sister to crown Archosauria (birds and crocodilians). Previously, a study using microRNAs (miRNAs) placed turtles inside diapsids, but as sister to lepidosaurs (lizards and Sphenodon) rather than archosaurs. Here, we test this hypothesis with an expanded miRNA presence/absence dataset, and employ more rigorous criteria for miRNA annotation. Significantly, we find no support for a turtle + lepidosaur sister-relationship; instead, we recover strong support for turtles sharing a more recent common ancestor with archosaurs. We further test this result by analyzing a super-alignment of precursor miRNA sequences for every miRNA inferred to have been present in the most recent common ancestor of tetrapods. This analysis yields a topology that is fully congruent with our presence/absence analysis; our results are therefore in accordance with most gene sequence studies, providing strong, consilient molecular evidence from diverse independent datasets regarding the phylogenetic position of turtles.
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Affiliation(s)
- Daniel J. Field
- Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - Jacques A. Gauthier
- Department of Geology and Geophysics, Yale University, 210 Whitney Avenue, New Haven, CT 06511, USA
| | - Benjamin L. King
- Mount Desert Island Biological Laboratory, Salisbury Cove, ME 04672, USA
| | - Davide Pisani
- School of Earth Sciences, University of Bristol, Queen’s Road, Bristol BS8 1RJ, United Kingdom and School of Biological Sciences, University of Bristol, Woodland Road, Bristol BS8 1UG, United Kingdom
| | - Tyler R. Lyson
- Smithsonian National Museum of Natural History, 10 Street and Constitution Avenue, Washington, DC 20013, USA
| | - Kevin J. Peterson
- Department of Biological Sciences, Dartmouth College, Hanover, NH 03755, USA
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Hirasawa T, Pascual-Anaya J, Kamezaki N, Taniguchi M, Mine K, Kuratani S. The evolutionary origin of the turtle shell and its dependence on the axial arrest of the embryonic rib cage. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2014; 324:194-207. [PMID: 24898540 DOI: 10.1002/jez.b.22579] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/04/2014] [Revised: 04/25/2014] [Accepted: 05/07/2014] [Indexed: 12/22/2022]
Abstract
Turtles are characterized by their possession of a shell with dorsal and ventral moieties: the carapace and the plastron, respectively. In this review, we try to provide answers to the question of the evolutionary origin of the carapace, by revising morphological, developmental, and paleontological comparative analyses. The turtle carapace is formed through modification of the thoracic ribs and vertebrae, which undergo extensive ossification to form a solid bony structure. Except for peripheral dermal elements, there are no signs of exoskeletal components ontogenetically added to the costal and neural bones, and thus the carapace is predominantly of endoskeletal nature. Due to the axial arrest of turtle rib growth, the axial part of the embryo expands laterally and the shoulder girdle becomes encapsulated in the rib cage, together with the inward folding of the lateral body wall in the late phase of embryogenesis. Along the line of this folding develops a ridge called the carapacial ridge (CR), a turtle-specific embryonic structure. The CR functions in the marginal growth of the carapacial primordium, in which Wnt signaling pathway might play a crucial role. Both paleontological and genomic evidence suggest that the axial arrest is the first step toward acquisition of the turtle body plan, which is estimated to have taken place after the divergence of a clade including turtles from archosaurs. The developmental relationship between the CR and the axial arrest remains a central issue to be solved in future.
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Affiliation(s)
- Tatsuya Hirasawa
- Laboratory for Evolutionary Morphology, RIKEN Center for Developmental Biology, Kobe, Japan
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Chen XH, Motani R, Cheng L, Jiang DY, Rieppel O. A carapace-like bony 'body tube' in an early triassic marine reptile and the onset of marine tetrapod predation. PLoS One 2014; 9:e94396. [PMID: 24718682 PMCID: PMC3981804 DOI: 10.1371/journal.pone.0094396] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/09/2014] [Accepted: 03/13/2014] [Indexed: 11/25/2022] Open
Abstract
Parahupehsuchus longus is a new species of marine reptile from the Lower Triassic of Yuan’an County, Hubei Province, China. It is unique among vertebrates for having a body wall that is completely surrounded by a bony tube, about 50 cm long and 6.5 cm deep, comprising overlapping ribs and gastralia. This tube and bony ossicles on the back are best interpreted as anti-predatory features, suggesting that there was predation pressure upon marine tetrapods in the Early Triassic. There is at least one sauropterygian that is sufficiently large to feed on Parahupehsuchus in the Nanzhang-Yuan’an fauna, together with six more species of potential prey marine reptiles with various degrees of body protection. Modern predators of marine tetrapods belong to the highest trophic levels in the marine ecosystem but such predators did not always exist through geologic time. The indication of marine-tetrapod feeding in the Nanzhang-Yuan’an fauna suggests that such a trophic level emerged for the first time in the Early Triassic. The recovery from the end-Permian extinction probably proceeded faster than traditionally thought for marine predators. Parahupehsuchus has superficially turtle-like features, namely expanded ribs without intercostal space, very short transverse processes, and a dorsal outgrowth from the neural spine. However, these features are structurally different from their turtle counterparts. Phylogeny suggests that they are convergent with the condition in turtles, which has a fundamentally different body plan that involves the folding of the body wall. Expanded ribs without intercostal space evolved at least twice and probably even more among reptiles.
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Affiliation(s)
- Xiao-hong Chen
- Wuhan Center of China Geological Survey, Wuhan, Hubei, P. R. China
| | - Ryosuke Motani
- Department of Earth and Planetary Sciences, University of California Davis, Davis, California, United States of America
| | - Long Cheng
- Wuhan Center of China Geological Survey, Wuhan, Hubei, P. R. China
| | - Da-yong Jiang
- Laboratory of Orogenic Belt and Crustal Evolution, Ministry of Education, Department of Geology and Geological Museum, Peking University, Beijing, P.R. China
| | - Olivier Rieppel
- Center of Integrative Research, The Field Museum, Chicago, Illinois, United States of America
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50
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Ezcurra MD, Scheyer TM, Butler RJ. The origin and early evolution of Sauria: reassessing the permian Saurian fossil record and the timing of the crocodile-lizard divergence. PLoS One 2014; 9:e89165. [PMID: 24586565 PMCID: PMC3937355 DOI: 10.1371/journal.pone.0089165] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2013] [Accepted: 01/14/2014] [Indexed: 11/19/2022] Open
Abstract
Sauria is the crown-group of Diapsida and is subdivided into Lepidosauromorpha and Archosauromorpha, comprising a high percentage of the diversity of living and fossil tetrapods. The split between lepidosauromorphs and archosauromorphs (the crocodile-lizard, or bird-lizard, divergence) is considered one of the key calibration points for molecular analyses of tetrapod phylogeny. Saurians have a very rich Mesozoic and Cenozoic fossil record, but their late Paleozoic (Permian) record is problematic. Several Permian specimens have been referred to Sauria, but the phylogenetic affinity of some of these records remains questionable. We reexamine and review all of these specimens here, providing new data on early saurian evolution including osteohistology, and present a new morphological phylogenetic dataset. We support previous studies that find that no valid Permian record for Lepidosauromorpha, and we also reject some of the previous referrals of Permian specimens to Archosauromorpha. The most informative Permian archosauromorph is Protorosaurus speneri from the middle Late Permian of Western Europe. A historically problematic specimen from the Late Permian of Tanzania is redescribed and reidentified as a new genus and species of basal archosauromorph: Aenigmastropheus parringtoni. The supposed protorosaur Eorasaurus olsoni from the Late Permian of Russia is recovered among Archosauriformes and may be the oldest known member of the group but the phylogenetic support for this position is low. The assignment of Archosaurus rossicus from the latest Permian of Russia to the archosauromorph clade Proterosuchidae is supported. Our revision suggests a minimum fossil calibration date for the crocodile-lizard split of 254.7 Ma. The occurrences of basal archosauromorphs in the northern (30°N) and southern (55°S) parts of Pangea imply a wider paleobiogeographic distribution for the group during the Late Permian than previously appreciated. Early archosauromorph growth strategies appear to be more diverse than previously suggested based on new data on the osteohistology of Aenigmastropheus.
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Affiliation(s)
- Martín D. Ezcurra
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- GeoBio-Center, Ludwig-Maximilian-Universität München, Munich, Germany
| | - Torsten M. Scheyer
- Paläontologisches Institut und Museum, Universität Zürich, Zurich, Switzerland
| | - Richard J. Butler
- School of Geography, Earth and Environmental Sciences, University of Birmingham, Edgbaston, Birmingham, United Kingdom
- GeoBio-Center, Ludwig-Maximilian-Universität München, Munich, Germany
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