Microcleidus
| Microcleidus Temporal range: Toarcian ~ | |
|---|---|
| Fossil M. homalospondylus | |
| Scientific classification | |
| Domain: | Eukaryota | 
| Kingdom: | Animalia | 
| Phylum: | Chordata | 
| Class: | Reptilia | 
| Superorder: | †Sauropterygia | 
| Order: | †Plesiosauria | 
| Family: | †Microcleididae | 
| Genus: | †Microcleidus Watson, 1909 | 
| Type species | |
| Plesiosaurus homalospondylus (Owen, 1865) | |
| Other species | |
| 
 | |
| Synonyms | |
| M. macropteus 
 M. tournemirensis 
 | |
Microcleidus is an extinct genus of sauropterygian reptile belonging to the Plesiosauroidea. The species has 40 neck vertebrae and a short tail of 28 vertebrae. Fossils of the genus have been found in France, the Posidonia Shale in Germany and Luxembourg, and the Alum Shale Formation of England.