Protorosaurus
| Protorosaurus Temporal range: Lopingian ~ | |
|---|---|
 | |
| Fossil specimen, Teyler's Museum | |
 | |
| Skeletal reconstruction from Jenkins et al., 2026 | |
Scientific classification  | |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Clade: | Archelosauria |
| Clade: | Archosauromorpha |
| Genus: | †Protorosaurus von Meyer 1830 |
| Species: | †P. speneri |
| Binomial name | |
| †Protorosaurus speneri von Meyer 1830 | |
Protorosaurus (from Greek: πρότερος próteros, 'earlier' and Greek: σαῦρος saûros, 'lizard') is an extinct genus of reptile. Members of the genus lived during the late Permian period in what is now Germany and Great Britain. Once believed to have been an ancestor to lizards, Protorosaurus is now known to be one of the oldest and most primitive members of Archosauromorpha, the group that would eventually lead to archosaurs such as crocodilians and dinosaurs.