Chelydridae

Chelydridae Temporal range: 70.6–0 Ma PreЄ Є O S D C P T J K Pg N Late Cretaceous[1] to Recent
The common snapping turtle (Chelydra serpentina) a species of Chelydridae
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Reptilia
Order:	Testudines
Suborder:	Cryptodira
Clade:	Polycryptodira
Family:	Chelydridae Gray, 1831[2]
Genera
Chelydra Macrochelys †Acherontemys †Chelydrops †Chelydropsis †Emarginachelys †Macrocephalochelys †Planiplastron †Protochelydra
Synonyms[3]
Chelydrae Gray, 1831:4[2] Chelydridae Swainson 1839:113[4] Chelydradae Gray, 1869:178[5]

The Chelydridae are a family of turtles which has seven extinct and two extant genera. The extant genera are Chelydra, the snapping turtles, and Macrochelys. Both are endemic to the Western Hemisphere. The extinct genera are Acherontemys, Chelydrops, Chelydropsis, Emarginachelys, Macrocephalochelys, Planiplastron, and Protochelydra.

Fossil history

The Chelydridae have a long fossil history, with extinct species reported from North America, all over Asia and Europe, far outside their present range. The earliest described chelydrid is Emarginachelys cretacea, known from well-preserved fossils from the Maastrichtian stage of the Late Cretaceous of Montana.^[1] Another well-preserved fossil chelydrid is the Late Paleocene Protochelydra zangerli from North Dakota.^[6] The carapace of P. zangerli is higher domed than that of the recent Chelydra, a trait conjectured to be associated with the coexistence of large, chelonivorous (i.e., turtle-eating) crocodilians. Another genus, Chelydropsis, contains several well-known Eurasian chelydrid species that existed from the Oligocene to the Pliocene.^[7]

Gallery

• 

  Chelydropsis murchisoni fossil remains: left: juvenile, right: adult

• 

  Common snapping turtle at Taum Sauk Mountain State Park

• 

  Two-year-old captive-raised snapping turtle from Pennsylvania

• 

  Female next to can to show size

References

1. Emarginachelys cretacea, Paleobiology Database
2. Gray, John Edward. (1831). Synopsis Reptilium; or Short Descriptions of the Species of Reptiles. Part I.—Cataphracta. Tortoises, Crocodiles, and Enaliosaurians. London: Treuttel, Wurz, and Co., 85 pp. [Published May 1831].
3. Turtle Taxonomy Working Group [van Dijk , P.P., Iverson, J.B., Shaffer, H.B., Bour, R., and Rhodin, A.G.J.]. (2012). Turtles of the world, 2012 update: annotated checklist of taxonomy, synonymy, distribution, and conservation status. Chelonian Research Monographs No. 5, pp. 000.243–000.328, doi:10.3854/crm.5.000.checklist.v5.2012, .
4. Swainson, William. (1839). On the natural history and classification of fishes, amphibians, and reptiles. Vol. II. In: Lardner, D. (Ed.). The Cabinet Cyclopaedia. Natural History. London: Longman, 452 pp.
5. Gray, John Edward. (1869). Notes on the families and genera of tortoises (Testudinata), and on the characters afforded by the study of their skulls. Proceedings of the Zoological Society of London 1869:165–225.
6. Danilov G. and J. F. Parham. (2008). A reassessment of some poorly known turtles from the Middle Jurassic of China, with comments on the antiquity of extant turtles. Journal of Vertebrate Paleontology 28(2):306-318
7. Böhme, M. (2008). Ectothermic vertebrates (Teleostei, Allocaudata, Urodela, Anura, Testudines, Choristodera, Crocodylia, Squamata) from the Upper Oligocene of Oberleichtersbach (Northern Bavaria, Germany). Courier Forschungsinstitut Senckenberg 260:161-183

• de Broin, F. (1969). Contribution a l’etude des cheloniens. Cheloniens continentaux du Cretace Superieur et du Tertiaire de France. Memoires du Muséum National d'Histoire Naturelle. Vol. C, No. XXVIII.
• Ericson, B. R. (1973). A new chelydrid turtle (Protochelydra zangerli), from the late Paleocene of North Dakota. Scientific Publications of the Science Museum of Minnesota, New Series. 2(2):1-16.
• Gaffney, E. S. (1975). Phylogeny of the chelydrid turtles: a study of shared derived characters in the skull. Fieldiana Geology 33:157-178.
• Parham, J. F., C.R. Feldman, and J. R. Boore. (2006). The complete mitochondrial genome of the enigmatic bigheaded turtle (Platysternon): description of unusual genomic features and the reconciliation of phylogenetic hypotheses based on mitochondrial and nuclear DNA. BMC Evol Biol. 6: 11. Published online February 7, 2006. doi:10.1186/1471-2148-6-11.
• Whetstone, K. N. (1978). A new genus of cryptodiran turtles (Testudinoidea, Chelydridae) from the Upper Cretaceous Hell Creek Formation of Montana. The University of Kansas Science Bulletin 51(17):539-563.