A Middle Triassic stem-turtle and the evolution of the turtle body plan

@article{Schoch2015AMT,
  title={A Middle Triassic stem-turtle and the evolution of the turtle body plan},
  author={Rainer R. Schoch and Hans‐Dieter Sues},
  journal={Nature},
  year={2015},
  volume={523},
  pages={584-587}
}
The origin and early evolution of turtles have long been major contentious issues in vertebrate zoology. This is due to conflicting character evidence from molecules and morphology and a lack of transitional fossils from the critical time interval. The ∼220-million-year-old stem-turtle Odontochelys from China has a partly formed shell and many turtle-like features in its postcranial skeleton. Unlike the 214-million-year-old Proganochelys from Germany and Thailand, it retains marginal teeth and… 
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TLDR
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TLDR
The morphology of Chinlechelys tenertesta supports the placement of Testudines outside of crown Sauria, as a taxon derived from pareiasaurs based on the morphology of the dorsal osteoderms and skull roof and reaffirm its unequivocal support for the composite model of costal bone formation in turtles.
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TLDR
A tiny new lepidosauromorph from the Middle Triassic from Vellberg (Germany), which combines a mosaic of features from both early evolving squamates and rhynchocephalians, such as the simultaneous occurrence of a splenial bone and partial development of acrodonty.
The diapsid origin of turtles.
A Review of the Fossil Record of Basal Mesozoic Turtles
  • W. Joyce
  • Environmental Science, Geography
    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.
Triassic turtle tracks and the origin of turtles
Abstract Turtle (Testudines) tracks, Chelonipus torquatus, reported from the early Middle Triassic (Anisian) of Germany, and Chelonipus isp. from the late Early Triassic (Spathian) of Wyoming and…
The early composition and evolution of the turtle shell (Reptilia, Testudinata)
The shell of the oldest true turtle (Testudinata) branch (Proterochersidae) from the Late Triassic (Norian) of Poland and Germany was built in its anterior and posterior part from an osteodermal…
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