Homology of the enigmatic nuchal bone reveals novel reorganization of the shoulder girdle in the evolution of the turtle shell

  title={Homology of the enigmatic nuchal bone reveals novel reorganization of the shoulder girdle in the evolution of the turtle shell},
  author={Tyler R. Lyson and Bhart‐Anjan S. Bhullar and Gabriel S Bever and Walter G. Joyce and Kevin de Queiroz and Arhat Abzhanov and Jacques A. Gauthier},
  journal={Evolution \& Development},
The turtle shell represents a unique modification of the ancestral tetrapod body plan. The homologies of its approximately 50 bones have been the subject of debate for more than 200 years. Although most of those homologies are now firmly established, the evolutionary origin of the dorsal median nuchal bone of the carapace remains unresolved. We propose a novel hypothesis in which the nuchal is derived from the paired, laterally positioned cleithra—dorsal elements of the ancestral tetrapod… 

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