The Jurassic turtles of North America. Bulletin of the AMNH ; v. 162, article 3

Supplemental Materials
Journal Title
Journal ISSN
Volume Title
New York : American Museum of Natural History
"There are two valid turtle taxa from the North American late Jurassic Morrison Formation: Glyptops plicatulus, distinguished by a fine, pustulose shell ornamentation, last vertebral scute partially dividing the last pair of marginal scutes, and a smoothly convex anterior margin of the plastron; and Dinochelys whitei, new genus and species, distinguished by a smooth shell surface, last vertebral scute not dividing the last pair of marginal scutes, and an anterior plastral margin with lobes formed by the gular and intergular scutes. presumed juveniles of Glyptops and Dinochelys suggest that prominent carapacial ridges characterize juveniles of these two taxa and that the ridges are lost in adults. Probaena sculpta Hay is considered a nomen dubium because it is an unidentifiable juvenile, presumably of Glyptops or Dinochelys. Taxa previously referred to Glyptops but here considered indeterminant are: 'Glyptops' pervicax, 'Glyptops' belviderensis, 'Glyptops' caelatus, 'Glyptops' depressus, and 'Glyptops' ruetimeyeri. Dinochelys is placed Cryptodira incertae sedis because the higher systematics of cryptodires is based on skull morphology and the skull is lacking in this form. A cranial study of Glyptops suggests that it and Mesochelys form a monophyletic group, the Glyptopsidae, that is characterized by one derived character: the basisphenoid extends the length of, and completely separates, the pterygoids. I follow Evans and Kemp's (1976) suggestion that the Baenoidea of Gaffney (1972 and 1975) is not monophyletic and that the Glyptopsidae is the sister group of the remaining cryptodires. Baenidae and Eucryptodira would form a monophyletic group sharing the derived character: posterior temporal emargination separating or nearly separating parietal and squamosal"--P. 95.
p. 93-135 : ill. ; 26 cm.
Includes bibliographical references (p. 134-135).