02260cam a2200349 i 4500 211095 20071022130727.0 760106s1975 ilua b 00010 eng 7516540 (OCoLC)ocm01991971 AAW-3499 DLC DLC UIU m.c.1 QE1 .F4 vol. 33, no. 9 QL666.C539 550/.8 s 598.1/3 Gaffney, Eugene S. Phylogeny of the chelydrid turtles : a study of shared derived characters in the skull / Eugene S. Gaffney --. Chelydrid turtles Chicago : Field Museum of Natural History, 1975. p. 157-178 : 6 ill. ; 24 cm. Fieldiana. Geology ; v. 33, no. 9 Field Museum of Natural History. Publication 1205 Caption title. "August 18, 1975." "This volume is dedicated to Dr. Rainer Zangerl." Includes bibliographical references (p. 176-178). The turtle genera Chelydra (Recent, North America), Macroclemys (Recent, North America), Platysternon (Recent, Asia), Protochelydra (Paleocene, North America), and Macrocephalochelys (Pliocene, Asia) are hypothesized as a strictly monophyletic group on the basis of a shared derived character study of the skull. The five genera are therefore placed in the Family Chelydridae. The primary characters used involved the degree of temporal and cheek emargination along with changes in bone size and shape in the skull roof. Protochelydra, with the most extensive emarginations is proposed as the primitive end of a morphocline series culminating in Platysternon, which has the least emarginate condition. Cranial diagnoses for the testudinoid families Chelydridae, Emydidae, and Testudinidae are included. Fieldiana series has been published as Geological Series by Field Columbian Museum (1895-1909) and Field Museum of Natural History (1909-1943), and as Fieldiana: Geology by Chicago Natural History Museum (1945-1966) and Field Museum of Natural History (1966-). Snapping turtles Turtles Classification. Reptiles Anatomy Skull Publication (Field Museum of Natural History) ; 1205.