The origin and loss of periodic patterning in the turtle shell

  title={The origin and loss of periodic patterning in the turtle shell},
  author={Jacqueline Emmanuel Moustakas-Verho and Roland Zimm and Judith A. Cebra-Thomas and Netta K. Lempi{\"a}inen and Aki Kallonen and Katherine L. Mitchell and Keijo H{\"a}m{\"a}l{\"a}inen and Isaac Salazar-Ciudad and Jukka Jernvall and Scott F. Gilbert},
  pages={3033 - 3039}
The origin of the turtle shell over 200 million years ago greatly modified the amniote body plan, and the morphological plasticity of the shell has promoted the adaptive radiation of turtles. The shell, comprising a dorsal carapace and a ventral plastron, is a layered structure formed by basal endochondral axial skeletal elements (ribs, vertebrae) and plates of bone, which are overlain by keratinous ectodermal scutes. Studies of turtle development have mostly focused on the bones of the shell… 

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