Charassognathus
Charassognathus (meaning 'notched jaw') is an extinct genus of Late Permian cynodonts. Described in 2007 from a locality near Fraserburg, South Africa, Charassognathus is the earliest and most basal cynodont. It is known only from the holotype, which dates from the upper Permian Period. The type and only species is C. gracilis. The holotype (SAM-PK-K 10369) is made up of a crushed skull, partial lower jaw and one leg.
| Charassognathus | |
|---|---|
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| Charassognathus gracilis, a basal cynodont | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Clade: | Therapsida |
| Clade: | Cynodontia |
| Family: | †Charassognathidae |
| Genus: | †Charassognathus Botha et al., 2007 |
| Species | |
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Charassognathus was a quadrupedal predator. It was named for a notch on its coronoid process which most likely was the insertion point for a chewing muscle, the adductor mandibulae externus. Charassognathus was a tiny animal, with a skull only 5 centimeters in length. Since the body of Charassognathus hasn't been discovered, its full length remains unknown, but estimates have been made at 50 centimeters.
Description
Charassognathus has a snout that makes up slightly less than half of the total length of its skull and a long facial process on its septomaxilla. Other than these two features its skull is that of a typical cynodont. The odd shape of its septomaxilla is more typical of therocephalians than other cynodonts indicating that it may be close to a common ancestor between the two groups.
See also
References
- Botha, Abdala & Smith (2007). "The oldest cynodont: new clues on the origin and diversification of the Cynodontia". Zoological Journal of the Linnean Society. 149: 477–492. doi:10.1111/j.1096-3642.2007.00268.x.