Kourisodon

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Kourisodon
Temporal range: Late Santonian - Late Maastrichtian
Kourisodon puntledgensis.jpg
Restored skull
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Sauropsida
Subclass: Diapsida
Order: Squamata
Family: Mosasauridae
Genus: Kourisodon
Nicholls and Meckert, 2002
Species

K. puntledgensis Nicholls and Meckert, 2002 (type)

Restored skeleton

Kourisodon ("razor tooth") is an extinct genus of mosasaur. Fossils have been found from Vancouver Island in British Columbia, Canada,[1] as well as from the Izumi Group of Japan.[2] These finds date back to the late Santonian stage and the late Campanian to the late Maastrichtian, respectively, of the Late Cretaceous. Kourisodon was originally described as a member of the "Leiodontini",[1] more recently as a "Clidastine".[3]

Distribution[edit]

Kourisodon puntledgensis is known from a single locality located in the Santonian Pender Formation along the banks of the Puntledge River (after which it was named). K. puntledgensis was a small mosasaur, with an estimated length of about 3.75 meters (around 12.3 feet). It shared its environment with a variety of Elasmosaurids, turtles, and other mosasaurs, although interestingly, it seems that no Polycotylids were present in its Pacific environment.[1]

In 2005, a fragmentary skeleton from exposures of the Izumi Group on Shikoku Island, Japan, was assigned to Kourisodon sp. This specimen demonstrated longer maxillary teeth among other differences from K. puntledgensis, which the authors interpreted to mean that this individual belonged to a second species, although this new species has not yet been formally named. Other fragmentary remains from the Izumi Group have been tentatively assigned to K. sp., some of which represent juvenile animals.[2]

References[edit]

  1. ^ a b c Nicholls, E. L. and Meckert, D. (2002). Marine reptiles from the Nanaimo Group (Upper Cretaceous) of Vancouver Island. Canadian Journal of Earth Science 39(11):1591-1603.
  2. ^ a b Tanimoto, M. (2005). "Mosasaur remains from the Upper Cretaceous Izumi Group of Southwest Japan." (PDF). Netherlands Journal of Geosciences. 84: 373–378. 
  3. ^ Caldwell, Michael; Konishi, Takuya (2007). "Taxonomic re-assignment of the first-known mosasaur specimen from Japan, and a discussion of circum-pacific mosasaur paleobiogeography". Journal of Vertebrate Paleontology. 27: 517–520. 

External links[edit]