Plethodus is an extinct genus of prehistoric ray-finned fish (Actinopterygii) belonging to the family Plethodidae within the order Tselfatiiformes. It is the type genus of the family Plethodidae.
Temporal Range: Cenomanian stage of the Late Cretaceous period.
Taxonomy:
- Kingdom: Animalia
- Phylum: Chordata
- Class: Actinopterygii
- Order: Tselfatiiformes
- Family: Plethodidae
- Genus: Plethodus
Species:
- P. expansus Dixon, 1850
- P. libycus Weiler, 1935
- P. oblongus Dixon, 1850
- P. pentagon Woodward, 1899
- P. tibniensis Schaal, 1984
Description: Plethodus is characterized by circular or slightly oblong tooth plates and a short, blunt rostrum (snout). It is known primarily from fragmentary fossils, including rostra (snout bones), tooth plates, and skull elements. The genus is considered an enigmatic snouted bony fish due to the incomplete nature of most fossil finds.
Fossil Distribution: Fossils of Plethodus have been recovered from Cenomanian-aged deposits in Europe (notably England), Egypt (Bahariya Formation), and the United States (Eagle Ford Group in Texas). The Texas specimens, described from the Britton Formation (Cenomanian–lower Turonian), represent some of the more recent discoveries of this genus outside of Europe and North Africa.
