Modeling neck mobility in fossil turtles.

摘要: Turtles have the unparalleled ability to retract their heads and necks within shell but little is known about evolution of this trait. Extensive analysis neck mobility in turtles using radiographs, CT scans, morphometry reveals that basal possessed less relative extant relatives, although anatomical prerequisites for modern were already established. Many are able achieve hypermobility by dislocating central articulations, which raises cautions reconstructing fossil vertebrates. A 3D-model Late Triassic turtle Proganochelys quenstedti early stem was its head tucking it sideways below shell. The simple ventrolateral bend seen turtle, however, contrasts with complex double-bend turtles. initial retraction therefore occurred a near-synchrony origin as place hide unprotected neck. In early, simplified mode, conical osteoderms on provided further protection. J. Exp. Zool. (Mol. Dev. Evol.) 324B: 230–243, 2015. © 2014 Wiley Periodicals, Inc.