Temporal range: Late Cretaceous
Fossil specimen, Houston Museum of Natural Science
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testudines
Suborder: Cryptodira
Clade: Panchelonioidea (?)
Family: Toxochelyidae
Baur, 1895
Genus: Toxochelys
Cope, 1873
  • T. latiremis Cope, 1873 (type)
  • T. moorevillensis Zangerl, 1953

Toxochelys (/txʌkɛlz/) is an extinct genus of marine turtle from the Late Cretaceous period. It is the most commonly found fossilized turtle species in the Smoky Hill Chalk, in western Kansas.[1]


Toxochelys had carapace about 48 centimetres (1.57 ft) in length.[2] Two species in the genus are recognized, Toxochelys latiremis and Toxochelys moorevillensis.[3] Phylogenetic analysis shows that Toxochelys belong to an extinct lineage of turtles transitional between modern sea turtles and other turtles.[4]

Toxochelys bauri Williston, 1905, based on the skeleton YPM 1786, is a synonym of Ctenochelys stenoporus.[5]


  1. ^ Retrieved on May 12, 2008
  2. ^ Farina, Bruna M.; Godoy, Pedro L.; Benson, Roger B. J.; Langer, Max C.; Ferreira, Gabriel S. (2023). "Turtle body size evolution is determined by lineage‐specific specializations rather than global trends". Ecology and Evolution. 13 (6). doi:10.1002/ece3.10201. ISSN 2045-7758. PMC 10293707. PMID 37384241.
  3. ^ Nicholls, E.L. 1988. New material of Toxochelys latiremis Cope, and a revision of the genus Toxochelys (Testudines, Chelonoidea). Journal of Vertebrate Paleontology, 8(2):181–187.
  4. ^ Kear BP, Lee MS (March 2006). "A primitive protostegid from Australia and early sea turtle evolution". Biol. Lett. 2 (1): 116–9. doi:10.1098/rsbl.2005.0406. PMC 1617175. PMID 17148342.
  5. ^ R. Zangerl. 1953. The vertebrate fauna of the Selma Formation of Alabama. Part IV. The turtles of the family Toxochelyidae. Fieldiana: Geology Memoirs 3(4):145–277.