Chamops

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Chamops
Temporal range: Late Cretaceous-Early Eocene, 84.5–55  Ma
Chamops holotype maxilla.png
Maxilla of the holotype seen from two different angles
Scientific classification Red Pencil Icon.png
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Squamata
Clade: Polyglyphanodontia
Genus: Chamops
Marsh, 1892
Type species
Chamops segnis
Marsh, 1892
Synonyms
  • Alethesaurus(Gilmore, 1928)
  • Lanceosaurus(Gilmore, 1928)

Chamops is an extinct genus of polyglyphanodontian lizard from the Late Cretaceous-Early Eocene of North America. Fossils have been found in the Hell Creek Formation, Judith River Formation and Polecat Bench Formation of Montana, [1] the Milk River Formation of Alberta, Canada and possibly also the Laramie Formation of Colorado. [2] It is known from only one species, C. segnis. [2] Chamops grew to approximately 0.5 meters (20 inches) long, and 2 kilograms (4 pounds) in weight. Unlike other polyglyphanodonts, Chamops had a more blunt snout. Chamops belonged to the Chamopsiid family of polyglyphanodonian lizards that lived in the Northern Hemisphere during the Late Cretaceous, although there are some possible Chamopsiid genera from South America and the Kem Kem Bone Beds in Morocco. It was originally thought Chamops and kin are related to whiptails, [2] although it is now thought they are more closely related to iguanas. [3]

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Bicuspidon is an extinct genus of Polyglyphanodontid lizard known from the Late Cretaceous of North America, Europe and Africa, two species, B. numerosus and B. smikros are known from the Cenomanian of Utah in the Mussentuchit Member of the Cedar Mountain Formation and the Naturita Formation respectively. While B. hatzegiensis is known from the Maastrichtian Sânpetru Formation of Romania and B. hogreli is known from the Cenomanian Kem Kem Beds of Morocco. An indeterminate taxon closely related to B. hatzegiensis referred to as B. aff. hatzegiensis is known from the Santonian Csehbánya Formation of Hungary. The dentition is heterodont, with conical anterior teeth and transversely orientated biscuspid posterior teeth.

Pelsochamops is an extinct genus of Chamopsiid lizard, containing the single species P. infrequens from the Santonian aged Csehbánya Formation of Hungary, known from a partial dentary and maxilla fragments. It is the first chamopsiid known from Europe, the rest being known from North America.

References

  1. D. E. Russell. (1967). Le Paleocene continental d'Amerique du nord. Memoires du Museum National d'Histoire Naturelle. Serie C., Sciences de la Terre 16(2):37-99
  2. 1 2 3 Marsh, O.C. (1892). "Notice of new reptiles from the Laramie formation". American Journal of Science. 43.
  3. R. L. Nydam and G. E. Voci. (2007). Teiid-like scincomorphan lizards from the Late Cretaceous (Campanian) of southern Utah. Journal of Herpetology 41(2):211-219