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Szczygielski T, Marchetti L, Dróżdż D. Natural external plastron mold of the Triassic turtle Proterochersis: An unusual mode of preservation. PLoS One 2024; 19:e0299314. [PMID: 38551910 PMCID: PMC10980221 DOI: 10.1371/journal.pone.0299314] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2023] [Accepted: 02/08/2024] [Indexed: 04/01/2024] Open
Abstract
Impressions of vertebrate bodies or their parts, such as trace fossils and natural molds of bones, are a valuable source of information about ancient faunas which may supplement the standard fossil record based on skeletal elements. Whereas trace fossils of animal activity are relatively common and actively studied within the field of ichnology, and natural impressions of internal or external surfaces are a frequent preservation mode in fossil invertebrates, natural molds of bones are comparatively rare and less extensively documented and discussed. Among them, internal molds (steinkerns) of turtle shells are a relatively well-known form of preservation, but the mechanisms and taphonomic prerequisites leading to their formation are poorly studied. External shell molds are even less represented in the literature. Herein, we describe a historic specimen of a natural external turtle plastron mold from the Triassic (Norian) Löwenstein Formation of Germany-a formation which also yielded a number of turtle steinkerns. The specimen is significant not only because it represents an unusual form of preservation, but also due to its remarkably large size and the presence of a potential shell pathology. Although it was initially interpreted as Proterochersis sp., the recent progress in the knowledge of proterochersid turtles leading to an increase in the number of known taxa within that group allows us to verify that assessment. We confirm that the specimen is morphologically consistent with the genus and tentatively identify it as Proterochersis robusta, the only representative of that genus from the Löwenstein Formation. We note, however, that its size exceeds the size observed thus far in Proterochersis robusta and fits within the range of Proterochersis porebensis from the Grabowa Formation of Poland. The marks interpreted as shell pathology are morphologically consistent with Karethraichnus lakkos-an ichnotaxon interpreted as a trace of ectoparasites, such as leeches. This may support the previously proposed interpretation of Proterochersis spp. as a semiaquatic turtle. Moreover, if the identification is correct, the specimen may represent a very rare case of a negative preservation of a named ichnotaxon. Finally, we discuss the taphonomy of the Löwenstein Formation turtles in comparison with other Triassic turtle-yielding formations which show no potential for the preservation of internal or external shell molds and propose a taphonomic model for the formation of such fossils.
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Affiliation(s)
| | - Lorenzo Marchetti
- Museum für Naturkunde, Leibniz-Institut für Evolutions-und Biodiversitätsforschung, Berlin, Germany
| | - Dawid Dróżdż
- Nalecz Institute of Biocybernetics and Biomedical Engineering, Polish Academy of Sciences, Warsaw, Poland
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Pedro Selvatti A, Romero Rebello Moreira F, Cardoso de Carvalho D, Prosdocimi F, Augusta de Moraes Russo C, Carolina Martins Junqueira A. Phylogenomics reconciles molecular data with the rich fossil record on the origin of living turtles. Mol Phylogenet Evol 2023; 183:107773. [PMID: 36977459 DOI: 10.1016/j.ympev.2023.107773] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 02/07/2023] [Accepted: 03/21/2023] [Indexed: 03/28/2023]
Abstract
Although a consensus exists that all living turtles fall within either Pleurodira or Cryptodira clades, estimating when these lineages split is still under debate. Most molecular studies date the split in the Triassic Period, whereas a Jurassic age is unanimous among morphological studies. Each hypothesis implies different paleobiogeographical scenarios to explain early turtle evolution. Here we explored the rich turtle fossil record with the Fossilized Birth-Death (FBD) and the traditional node dating (ND) methods using complete mitochondrial genomes (147 taxa) and a set of nuclear orthologs with over 10 million bp (25 taxa) to date the major splits in Testudines. Our results support an Early Jurassic split (191-182 Ma) for the crown Testudines with great consistency across different dating methods and datasets, with a narrow confidence interval. This result is independently supported by the oldest fossils of Testudines that postdate the Middle Jurassic (174 Ma), which were not used for calibration in this study. This age coincides with the Pangaea fragmentation and the formation of saltwater barriers such as the Atlantic Ocean and the Turgai Strait, supporting that diversification in Testudines was triggered by vicariance. Our ages of the splits in Pleurodira coincide with the geologic events of the Late Jurassic and Early Cretaceous. Conversely, the early Cryptodira radiation remained in Laurasia, and its diversification ensued as all its major lineages expanded their distribution into every continent during the Cenozoic. We provide the first detailed hypothesis of the evolution of Cryptodira in the Southern Hemisphere, in which our time estimates are correlated with each contact between landmasses derived from Gondwana and Laurasia. Although most South American Cryptodira arrived through the Great American Biotic Interchange, our results indicate that the Chelonoidis ancestor probably arrived from Africa through the chain islands of the South Atlantic during the Paleogene. Together, the presence of ancient turtle diversity and the vital role that turtles occupy in marine and terrestrial ecosystems underline South America as a chief area for conservation.
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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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Szczygielski T. Obscure by name: solving the enigma of Chelytherium obscurum, the first described Triassic turtle. Zool J Linn Soc 2020. [DOI: 10.1093/zoolinnean/zlaa139] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
Abstract
The material historically referred to Chelytherium obscurum is exceptional for a number of reasons. It is the first described Triassic turtle, the oldest testudinate among the British palaeontological collections, and it is one of the oldest testudinates in the world. Nevertheless, after its establishment in 1863, the taxon remained in a taxonomic limbo and was eventually almost forgotten. However, the recent reconsideration of proterochersid turtles, with improved understanding of their anatomy, allows reassessment of Chelytherium obscurum as a member of the Proterochersidae, subjectively synonymous with Proterochersis robusta. Despite nomenclatural priority, in accordance with the suggestions of previous authors, the name Proterochersis robusta is endorsed to be upheld.
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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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Joyce WG, Bandyopadhyay S. A reevaluation of the basal turtle Indochelys spatulata from the Early-Middle Jurassic (Toarcian-Aalenian) of India, with descriptions of new material. PeerJ 2020; 8:e8542. [PMID: 32095362 PMCID: PMC7020818 DOI: 10.7717/peerj.8542] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2019] [Accepted: 01/09/2020] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Indochelys spatulata is an extinct turtle from the Early to Middle Jurassic Kota Formation of the Pranhita-Godavari Gondwana basin, India. The holotype and previously only known specimen is a partially eroded shell that had been collected near Kota village, north of Sironcha, in Maharashtra State. Phylogenetic analyses have consistently suggested placement at the base of the clade Mesochelydia. METHODS We here figure and describe the holotype of Indochelys spatulata and two new specimens, which were collected from the Kota Formation near Kistapur village, Telengana State, about 60 km NW from the type locality. We furthermore explore the relationships of this fossil turtle by updating its scoring based on all available material in the most recent analysis of basal turtle relationships. RESULTS The revision of the holotype of Indochelys spatulata provides minor adjustments to the morphology of this specimen, in particular recognition of a transverse break across the carapace, presence of only eight neurals, of which the eight is octagonal, and presence of a pathological element located between neurals VII and VIII. The new material provides new anatomical insights, in particular presence of a broad cervical, a vertebral V that inserts deeply into vertebral IV, narrow pleurals within increasingly short posteromedial contacts with the vertebrals towards the posterior, at least three pairs of musk duct foramina, and numerous insights into the morphology of the girdles and stylopodium. In combination, all material allows affirming the validity of Indochelys spatulata with confidence. The phylogenetic analysis affirms the placement of Indochelys spatulata as a basal mesochelydian, but cannot resolve its relationships relative to the roughly coeval Condorchelys antiqua and Kayentachelys aprix.
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Affiliation(s)
- Walter G. Joyce
- Department of Geosciences, University of Fribourg, Fribourg, Switzerland
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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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Williams C, Stayton CT. Effects of Sutured Pelvic Elements on Turtle Shell Strength: A Comparison of Pleurodire and Cryptodire Shell Mechanics. HERPETOLOGICA 2019. [DOI: 10.1655/d-17-00066] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Affiliation(s)
- Cameron Williams
- Department of Biology, Bucknell University, Lewisburg, PA 17837, USA
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Shaffer HB, McCartney-Melstad E, Near TJ, Mount GG, Spinks PQ. Phylogenomic analyses of 539 highly informative loci dates a fully resolved time tree for the major clades of living turtles (Testudines). Mol Phylogenet Evol 2017; 115:7-15. [PMID: 28711671 DOI: 10.1016/j.ympev.2017.07.006] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2016] [Revised: 05/30/2017] [Accepted: 07/10/2017] [Indexed: 10/19/2022]
Abstract
Accurate time-calibrated phylogenies are the centerpiece of many macroevolutionary studies, and the relationship between the size and scale of molecular data sets and the density and accuracy of fossil calibrations is a key element of time tree studies. Here, we develop a target capture array specifically for living turtles, compare its efficiency to an ultraconserved element (UCE) dataset, and present a time-calibrated molecular phylogeny based on 539 nuclear loci sequenced from 26 species representing the breadth of living turtle diversity plus outgroups. Our gene array, based on three fully sequenced turtle genomes, is 2.4 times more variable across turtles than a recently published UCE data set for an identical subset of 13 species, confirming that taxon-specific arrays return more informative data per sequencing effort than UCEs. We used our genomic data to estimate the ages of living turtle clades including a mid-late Triassic origin for crown turtles and a mid-Carboniferous split of turtles from their sister group, Archosauria. By specifically excluding several of the earliest potential crown turtle fossils and limiting the age of fossil calibration points to the unambiguous crown lineage Caribemys oxfordiensis from the Late Jurassic (Oxfordian, 163.5-157.3Ma) we corroborate a relatively ancient age for living turtles. We also provide novel age estimates for five of the ten testudine families containing more than a single species, as well as several intrafamilial clades. Most of the diversity of crown turtles appears to date to the Paleogene, well after the Cretaceous-Paleogene mass extinction 66mya.
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Affiliation(s)
- H Bradley Shaffer
- Department of Ecology and Evolutionary Biology, La Kretz Center for California Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA.
| | - Evan McCartney-Melstad
- Department of Ecology and Evolutionary Biology, La Kretz Center for California Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA
| | - Thomas J Near
- Department of Ecology and Evolutionary Biology, Yale University, New Haven, CT 06520, USA
| | - Genevieve G Mount
- Department of Ecology and Evolutionary Biology, La Kretz Center for California Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA; Department of Biological Sciences, Museum of Natural Science, 119 Foster Hall, Louisiana State University, Baton Rouge, LA 70803, USA
| | - Phillip Q Spinks
- Department of Ecology and Evolutionary Biology, La Kretz Center for California Conservation Science, and Institute of the Environment and Sustainability, University of California, Los Angeles, CA 90095, USA
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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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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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Anquetin J, Tong H, Claude J. A Jurassic stem pleurodire sheds light on the functional origin of neck retraction in turtles. Sci Rep 2017; 7:42376. [PMID: 28206991 PMCID: PMC5312562 DOI: 10.1038/srep42376] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/31/2016] [Accepted: 01/09/2017] [Indexed: 11/17/2022] Open
Abstract
Modern turtles are composed of two monophyletic groups, notably diagnosed by divergent neck retraction mechanisms. Pleurodires (side-necked turtles) bend their neck sideways and protect their head under the anterior margin of the carapace. Cryptodires (hidden-necked turtles) withdraw their neck and head in the vertical plane between the shoulder girdles. These two mechanisms of neck retraction appeared independently in the two lineages and are usually assumed to have evolved for protective reasons. Here we describe the neck of Platychelys oberndorferi, a Late Jurassic early stem pleurodire, and find remarkable convergent morphological and functional similarities with modern cryptodires. Partial vertical neck retraction in this taxon is interpreted to have enabled fast forward projection of the head during underwater prey capture and offers a likely explanation to the functional origin of neck retraction in modern cryptodires. Complete head withdrawal for protection may therefore have resulted from an exaptation in that group.
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Affiliation(s)
- Jérémy Anquetin
- JURASSICA Museum, Porrentruy, Switzerland.,Department of Geosciences, University of Fribourg, Fribourg, Switzerland
| | - Haiyan Tong
- Palaeontological Research and Education Centre, Mahasarakham University, Mahasarakham, Thailand
| | - Julien Claude
- Institut des Sciences de l'Evolution de Montpellier, UMR 5554 CNRS/UM/IRD/EPHE, Montpellier, France
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Joyce WG, Rabi M, Clark JM, Xu X. A toothed turtle from the Late Jurassic of China and the global biogeographic history of turtles. BMC Evol Biol 2016; 16:236. [PMID: 27793089 PMCID: PMC5084352 DOI: 10.1186/s12862-016-0762-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2016] [Accepted: 09/06/2016] [Indexed: 11/11/2022] Open
Abstract
BACKGROUND Turtles (Testudinata) are a successful lineage of vertebrates with about 350 extant species that inhabit all major oceans and landmasses with tropical to temperate climates. The rich fossil record of turtles documents the adaptation of various sub-lineages to a broad range of habitat preferences, but a synthetic biogeographic model is still lacking for the group. RESULTS We herein describe a new species of fossil turtle from the Late Jurassic of Xinjiang, China, Sichuanchelys palatodentata sp. nov., that is highly unusual by plesiomorphically exhibiting palatal teeth. Phylogenetic analysis places the Late Jurassic Sichuanchelys palatodentata in a clade with the Late Cretaceous Mongolochelys efremovi outside crown group Testudines thereby establishing the prolonged presence of a previously unrecognized clade of turtles in Asia, herein named Sichuanchelyidae. In contrast to previous hypotheses, M. efremovi and Kallokibotion bajazidi are not found within Meiolaniformes, a clade that is here reinterpreted as being restricted to Gondwana. CONCLUSIONS A revision of the global distribution of fossil and recent turtle reveals that the three primary lineages of derived, aquatic turtles, including the crown, Paracryptodira, Pan-Pleurodira, and Pan-Cryptodira can be traced back to the Middle Jurassic of Euramerica, Gondwana, and Asia, respectively, which resulted from the primary break up of Pangaea at that time. The two primary lineages of Pleurodira, Pan-Pelomedusoides and Pan-Chelidae, can similarly be traced back to the Cretaceous of northern and southern Gondwana, respectively, which were separated from one another by a large desert zone during that time. The primary divergence of crown turtles was therefore driven by vicariance to the primary freshwater aquatic habitat of these lineages. The temporally persistent lineages of basal turtles, Helochelydridae, Meiolaniformes, Sichuanchelyidae, can similarly be traced back to the Late Mesozoic of Euramerica, southern Gondwana, and Asia. Given the ambiguous phylogenetic relationships of these three lineages, it is unclear if their diversification was driven by vicariance as well, or if they display a vicariance-like pattern. The clean, primary signal apparent among early turtles is secondarily obliterated throughout the Late Cretaceous to Recent by extensive dispersal of continental turtles and by multiple invasions of marine habitats.
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Affiliation(s)
- Walter G. Joyce
- Department of Geosciences, University of Fribourg, Chemin de Musée 6, 1700 Fribourg, Switzerland
| | - Márton Rabi
- Department of Geosciences, University of Tübingen, Hölderlinstrasse 12, 72074 Tübingen, Germany
- Department of Geosciences, University of Turin, Via Valperga Caluso 35, 10125 Torino, Italy
| | - James M. Clark
- Department of Biological Sciences, George Washington University, 800 22nd Street, NW, Suite 6000, Washington, DC 20052 USA
| | - Xing Xu
- Key Laboratory of Vertebrate Evolution and Human Origin of Chinese Academy of Sciences, Institute of Vertebrate Paleontology & Paleoanthropology, Chinese Academy of Sciences, 142 Xizhimenwai Street, Beijing, 100044 China
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Joyce WG, Lyson TR, Kirkland JI. An early bothremydid (Testudines, Pleurodira) from the Late Cretaceous (Cenomanian) of Utah, North America. PeerJ 2016; 4:e2502. [PMID: 27703852 PMCID: PMC5045886 DOI: 10.7717/peerj.2502] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Accepted: 08/29/2016] [Indexed: 11/20/2022] Open
Abstract
BACKGROUND Bothremydidae is a clade of extinct pleurodiran turtles known from the Cretaceous to Paleogene of Africa, Europe, India, Madagascar, and North and South America. The group is most diverse during the Late Cretaceous to Paleogene of Africa. Little is known, however, about the early evolution of the group. METHODS We here figure and describe a fossil turtle from early Late Cretaceous deposits exposed at MacFarlane Mine in Cedar Canyon, southwestern Utah, USA. The sediments associated with the new turtle are utilized to infer its stratigraphic provenience and the depositional settings in which it was deposited. The fossil is compared to previously described fossil pleurodires, integrated into a modified phylogenetic analysis of pelomedusoid turtles, and the biogeography of bothremydid turtles is reassessed. In light of the novel phylogenetic hypotheses, six previously established taxon names are converted to phylogenetically defined clade names to aid communication. RESULTS The new fossil turtle can be inferred with confidence to have originated from a brackish water facies within the late Cenomanian Culver Coal Zone of the Naturita Formation. The fossil can be distinguished from all other previously described pleurodires and is therefore designated as a new taxon, Paiutemys tibert gen. et. sp. nov. Phylogenetic analysis places the new taxon as sister to the European Polysternon provinciale, Foxemys trabanti and Foxemys mechinorum at the base of Bothremydinae. Biogeographic analysis suggests that bothremydids originated as continental turtles in Gondwana, but that bothremydines adapted to near-shore marine conditions and therefore should be seen as having a circum-Atlantic distribution.
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Affiliation(s)
- Walter G. Joyce
- Departement für Geowissenschaften, Universität Freiburg, Freiburg, Switzerland
| | - Tyler R. Lyson
- Department of Earth Sciences, Denver Museum of Nature and Science, Denver, CO, USA
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15
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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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16
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Mayerl CJ, Brainerd EL, Blob RW. Pelvic girdle mobility of cryptodire and pleurodire turtles during walking and swimming. ACTA ACUST UNITED AC 2016; 219:2650-8. [PMID: 27340204 DOI: 10.1242/jeb.141622] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2016] [Accepted: 06/15/2016] [Indexed: 11/20/2022]
Abstract
Movements of the pelvic girdle facilitate terrestrial locomotor performance in a wide range of vertebrates by increasing hind limb excursion and stride length. The extent to which pelvic movements contribute to limb excursion in turtles is unclear because the bony shell surrounding the body presents a major obstacle to their visualization. In the Cryptodira, which are one of the two major lineages of turtles, pelvic anatomy indicates the potential for rotation inside the shell. However, in the Pleurodira, the other major suborder, the pelvis shows a derived fusion to the shell, preventing pelvic motion. In addition, most turtles use their hind limbs for propulsion during swimming as well as walking, and the different locomotor demands between water and land could lead to differences in the contributions of pelvic rotation to limb excursion in each habitat. To test these possibilities, we used X-ray reconstruction of moving morphology (XROMM) to compare pelvic mobility and femoral motion during walking and swimming between representative species of cryptodire (Pseudemys concinna) and pleurodire (Emydura subglobosa) turtles. We found that the pelvis yawed substantially in cryptodires during walking and, to a lesser extent, during swimming. These movements contributed to greater femoral protraction during both walking and swimming in cryptodires when compared with pleurodires. Although factors related to the origin of pelvic-shell fusion in pleurodires are debated, its implications for their locomotor function may contribute to the restriction of this group to primarily aquatic habits.
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Affiliation(s)
| | - Elizabeth L Brainerd
- Department of Ecology and Evolutionary Biology, Brown University, Providence, RI 02912, USA
| | - Richard W Blob
- Department of Biological Sciences, Clemson University, Clemson, SC 29634, USA
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17
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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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18
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Héritier L, Badets M, Du Preez LH, Aisien MS, Lixian F, Combes C, Verneau O. Evolutionary processes involved in the diversification of chelonian and mammal polystomatid parasites (Platyhelminthes, Monogenea, Polystomatidae) revealed by palaeoecology of their hosts. Mol Phylogenet Evol 2015; 92:1-10. [DOI: 10.1016/j.ympev.2015.05.026] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2015] [Revised: 05/27/2015] [Accepted: 05/29/2015] [Indexed: 11/16/2022]
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19
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Cadena E, Joyce WG. A Review of the Fossil Record of Turtles of the CladesPlatychelyidaeandDortokidae. BULLETIN OF THE PEABODY MUSEUM OF NATURAL HISTORY 2015. [DOI: 10.3374/014.056.0101] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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20
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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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21
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Rice R, Riccio P, Gilbert SF, Cebra-Thomas J. Emerging from the rib: resolving the turtle controversies. JOURNAL OF EXPERIMENTAL ZOOLOGY PART B-MOLECULAR AND DEVELOPMENTAL EVOLUTION 2015; 324:208-20. [PMID: 25675951 DOI: 10.1002/jez.b.22600] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2014] [Accepted: 09/29/2014] [Indexed: 12/15/2022]
Abstract
Two of the major controversies in the present study of turtle shell development involve the mechanism by which the carapacial ridge initiates shell formation and the mechanism by which each rib forms the costal bones adjacent to it. This paper claims that both sides of each debate might be correct-but within the species examined. Mechanism is more properly "mechanisms," and there is more than one single way to initiate carapace formation and to form the costal bones. In the initiation of the shell, the rib precursors may be kept dorsal by either "axial displacement" (in the hard-shell turtles) or "axial arrest" (in the soft-shell turtle Pelodiscus), or by a combination of these. The former process would deflect the rib into the dorsal dermis and allow it to continue its growth there, while the latter process would truncate rib growth. In both instances, though, the result is to keep the ribs from extending into the ventral body wall. Our recent work has shown that the properties of the carapacial ridge, a key evolutionary innovation of turtles, differ greatly between these two groups. Similarly, the mechanism of costal bone formation may differ between soft-shell and hard-shell turtles, in that the hard-shell species may have both periosteal flattening as well as dermal bone induction, while the soft-shelled turtles may have only the first of these processes.
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Affiliation(s)
- Ritva Rice
- Institute of Biotechnology, University of Helsinki, Helsinki, Finland
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22
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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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Lawver DR, Jackson FD. A Review of the Fossil Record of Turtle Reproduction: Eggs, Embryos, Nests and Copulating Pairs. BULLETIN OF THE PEABODY MUSEUM OF NATURAL HISTORY 2014. [DOI: 10.3374/014.055.0210] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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24
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Romano PSR, Gallo V, Ramos RRC, Antonioli L. Atolchelys lepida, a new side-necked turtle from the Early Cretaceous of Brazil and the age of crown Pleurodira. Biol Lett 2014; 10:20140290. [PMID: 25079494 PMCID: PMC4126622 DOI: 10.1098/rsbl.2014.0290] [Citation(s) in RCA: 40] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/11/2014] [Accepted: 07/08/2014] [Indexed: 11/12/2022] Open
Abstract
We report a new pleurodiran turtle from the Barremian Morro do Chaves Formation, Sergipe-Alagoas Basin, Brazil. We tested the phylogenetic position of Atolchelys lepida gen. et sp. nov. by including it in a comprehensive cladistic analysis of pleurodires. The new species is a basal member of Bothremydidae and simultaneously the oldest unambiguous crown Pleurodira. The biogeographic and chronostratigraphic significance of the finding has implications for the calibration of molecular clocks studies by pushing back the minimum age of crown Pleurodira by more than 12 Ma (ca 125 Ma). The reanalysis of Pelomedusoides relationships provides evidence that the early evolution and relationships among the main lineages of side-necked turtles can be explained, at least partially, by a sequence of vicariance events.
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Affiliation(s)
- Pedro S R Romano
- Departamento de Biologia Animal, Universidade Federal de Viçosa, Viçosa, Minas Gerais CEP 36570-900, Brazil
| | - Valéria Gallo
- Departamento de Zoologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro CEP 20550-013, Brazil
| | - Renato R C Ramos
- Museu Nacional, Departamento de Geologia e Paleontologia, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro CEP 20940-040, Brazil
| | - Luzia Antonioli
- Departamento de Estratigrafia e Paleontologia, Universidade do Estado do Rio de Janeiro, Rio de Janeiro, Rio de Janeiro CEP 20550-013, Brazil
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