Semionotus
| Semionotus | |
|---|---|
| Fossils of S. bergeri | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Class: | Actinopterygii | 
| Clade: | Ginglymodi | 
| Order: | †Semionotiformes | 
| Superfamily: | †Semionotoidea | 
| Family: | †Semionotidae | 
| Genus: | †Semionotus Agassiz, 1843 | 
Semionotus (from Greek: σημιον semion, 'mark' and Greek: νῶτος nôtos, 'back') is an extinct genus of ray-finned fish found throughout Northern Pangaea (North America and Europe) during the late Triassic, becoming extinct in the Early Jurassic.