Cynodesmus

Cynodesmus Temporal range: Late Oligocene to Early Miocene
Scientific classification
Kingdom:	Animalia
Phylum:	Chordata
Class:	Mammalia
Order:	Carnivora
Family:	Canidae
Subfamily:	†Hesperocyoninae
Genus:	†Cynodesmus Scott, 1895
Type species
†Cynodesmus thooides
Species
†C. martini †C. thooides

Cynodesmus is an extinct genus of canine which inhabited North America 34 Mya to 25 Mya (Wang, 1994).

The 1 m (3 ft 4 in) long creature was one of the first canids to truly look dog-like. It probably looked like the modern coyote, but had a shorter skull, heavier tail and longer rump. Also, Cynodesmus was not a very good runner compared to most other canids; it probably attacked prey from an ambush. Like felids, it could (partially) retract its claws.

Taxonomy

Cynodesmus once included numerous species of Oligocene and Miocene canid with highly carnivorous (hypercarnivorous) dentitions. A revision of the genus by Wang (1994) indicates that most species previously placed in Cynodesmus are unrelated to the type species, C. thooides. These other species have been placed the genera Carpocyon, Desmocyon, Leptocyon, Metatomarctus, Osbornodon, Otarocyon, Paracynarctus, Paratomarctus, and Phlaocyon (Wang, 1994; Wang et al., 1999). Of these, only Osbornodon belongs in the same subfamily as Cynodesmus, Hesperocyoninae. The remaining genera are placed in the subfamilies Borophaginae and Caninae.

With unrelated species removed, Cynodesmus is currently restricted to the type species and the closely related C. martini (Wang, 1994).

Studies using the old conception of Cynodesmus considered it to be the ancestor of Tomarctus (16-23 Ma) from which wolves, dogs, foxes and fennecs developed. The Cynodesmus is a good example of convergent evolution because of other species such as the Borophagus, the largest and most dominant canids of this Pliocene epoch, both of which evolved from it.

References

• Wang, X. 1994. Phylogenetic systematics of the Hesperocyoninae (Carnivora, Canidae). Bulletin of the American Museum of Natural History, 221:1-207.
• Wang, X., R.H. Tedford, and B.E. Taylor. 1999. Phylogenetic systematics of the Borophaginae (Carnivora, Canidae). Bulletin of the American Museum of Natural History, 243:1-391.