Transitional fossils and the origin of turtles

@article{Lyson2010TransitionalFA,
  title={Transitional fossils and the origin of turtles},
  author={T. Lyson and G. S. Bever and B. Bhullar and W. Joyce and J. Gauthier},
  journal={Biology Letters},
  year={2010},
  volume={6},
  pages={830 - 833}
}
The origin of turtles is one of the most contentious issues in systematics with three currently viable hypotheses: turtles as the extant sister to (i) the crocodile–bird clade, (ii) the lizard–tuatara clade, or (iii) Diapsida (a clade composed of (i) and (ii)). We reanalysed a recent dataset that allied turtles with the lizard–tuatara clade and found that the inclusion of the stem turtle Proganochelys quenstedti and the ‘parareptile’ Eunotosaurus africanus results in a single overriding… Expand
The origin of turtles: a paleontological perspective.
  • W. Joyce
  • Biology, Medicine
  • Journal of experimental zoology. Part B, Molecular and developmental evolution
  • 2015
TLDR
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. Expand
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It is now possible to develop a comprehensive scenario for the sequence of evolutionary changes leading to the formation of the turtle body plan within a phylogenetic framework and evaluate it in light of the ontogenetic development of the shell in extant turtles. Expand
Evolutionary origin of the turtle skull
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High-resolution computed tomography and a novel character/taxon matrix are used 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. Expand
A Review of the Fossil Record of Basal Mesozoic Turtles
  • W. Joyce
  • Biology
  • Bulletin of the Peabody Museum of Natural History
  • 2017
TLDR
Sedimentological, anatomical, and histological data universally hint at terrestrial habitat preference among the earliest stem turtles, but a more mixed, though unambiguously continental signal is apparent further towards the crown. Expand
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TLDR
A model of shell assembly that makes predictions for the as-yet unestablished history of the turtle stem group is built on by integrating novel data for Eunotosaurus africanus, which is congruent with molecular-based divergence estimates for the lineage, and remains viable whether turtles originated inside or outside crown Diapsida. Expand
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A novel molecular dataset, the presence versus absence of specific microRNAs, is applied to the problem of the phylogenetic position of turtles and the root of the reptilian tree, and it is found that this dataset unambiguously supports a turtle + lepidosaur group. Expand
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A new phylogenetic hypothesis informed by high resolution computed tomographic data of living and fossil taxa is presented, indicating three independent evolutionary transitions to marine life in non‐pleurodiran turtles (plus an additional two‐three in pleurodires). Expand
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A Triassic stem turtle from China is described that has a mixture of derived characters and plesiomorphic features, including an edentulous beak and a rigid puboischiadic plate. Expand
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