Carinodens
Carinodens Temporal range: Late Cretaceous, Maastrichtian
| |
---|---|
Jaw of Carinodens belgicus | |
Scientific classification | |
Domain: | Eukaryota |
Kingdom: | Animalia |
Phylum: | Chordata |
Class: | Reptilia |
Order: | Squamata |
Clade: | †Mosasauria |
Superfamily: | †Mosasauroidea |
Family: | †Mosasauridae |
Tribe: | †Globidensini |
Genus: | †Carinodens Thurmond, 1969 |
Species | |
| |
Synonyms | |
|
Carinodens is an
Carinodens is widely considered a
Description
Carinodens measured about 2–2.6 metres (6.6–8.5 ft) in length and is one of the smallest known mosasaurs.[4][3][5] It was closely related to Globidens, though is scantly known in comparison. The holotype specimen consists of an incomplete right dentary and most subsequently referred fossils are isolated teeth. The holotype dentary only preserves the posteriormost teeth, meaning that until recently when more comprehensive material was recovered, most of the dentition of the genus (its most distinctive feature) was unknown.[6]
Carinodens can easily be distinguished from the closely related Globidens by the compressed nature of its teeth and its relatively delicate dentary.[7]
Russell (1967) offered a brief diagnosis (due to the fragmentary nature of the fossils) of the genus, then known as Compressidens: "Small projection of dentary anterior to first dentary tooth. Median dentary teeth bilaterally compressed, bicarinate, subrectangular in lateral view and with pointed apices. Anterior teeth circular in cross-section with strongly recurved pointed apices".[7]
Dentition
By mosasaur standards, the teeth of Carinodens are unusually
Diet
Carinodens, like the related Globidens, is considered to have been a durophagous mosasaur. Because the anteriormost part of the dentary of Carinodens is relatively slender with small pointed tooth crowns, only the posteriormost five teeth actually functioned for crushing food. The anteriormost portion of the dentary was thus likely used for acquiring and handling food rather than crushing it, an idea already suggested by Dollo (1913) during the description of the type species. The maxilla of Carinodens is unknown, which hinders knowledge on the interaction between the lower and upper jaw.[6]
Dollo (1913, 1924) suggested a diet dominated by
Classification
Carinodens fraasi was first described and illustrated by Louis Dollo in 1913 as "Globidens fraasi". Dollo later erected a separate genus, "Compressidens" for the species in 1924, recognising the more compressed nature of the teeth in comparison to those of Globidens. Dollo also assigned Bottosaurus belgicus, previously misinterpreted as a species of crocodilian, to the genus as Compressidens belgicus. With the name Compressidens being preoccupied by a scaphopod mollusk, Thurmond (1969) proposed the substitute name Carinodens.[6]
Carinodens is most frequently recovered as a sister taxon to Globidens within the Globidensini tribe in the Mosasaurinae. The cladogram below, covering the Globidensini, is based upon a summary of evolutionary adaptations in the Globidensini featured in Schulp et al. (2004):[6]
Globidensini |
| ||||||||||||
It is worth noting that placing Prognathodon within the Globidensini is controversial, and it is most often seen as either a more basal mosasaurine or as part of its own tribe, the Prognathodontini.
The primary feature distinguishing the two recognised species, C. fraasi and C. belgicus is found in their dentition. The teeth of C. fraasi are unicuspid and the teeth of C. belgicus are tricuspid.
References
- ^ J. T. Thurmond. 1969. New name for the mosasaur Compressidens Dollo, 1924. Journal of Paleontology 43(5):1298
- ^ Kaddumi H. F. 2009. The first and most complete Carinodens (Squamata: Mosasauridae) skeleton yet with a description of a new species from the Harrana Fauna. In: Fossils of the Harrana Fauna and the Adjacent Areas. Publications of the Eternal River Museum of Natural History, Amman, pp 49-64
- ^ ISSN 0374-955X.
- ^ .
- .
- ^ ISSN 0272-4634.
- ^ a b c Russell, Dale. A. (6 November 1967). "Systematics and Morphology of American Mosasaurs" (PDF). Bulletin of the Peabody Museum of Natural History (Yale University). Archived from the original (PDF) on 24 June 2016. Retrieved 30 September 2017.