Hadrianus is an extinct genus of tortoise belonging to the Testudinidae[1] found in the United States, the Yolomécatl Formation of Mexico, the Alai Beds of Kyrgyzstan and Spain[citation needed] and believed to be the oldest true tortoise known.[3] The genus is thought to be closely related to the genus Manouria.[3] The genus may have evolved in the subtropics of Asia and subsequently migrated to North America and Europe.[3] Evangelos Vlachos (2018) reassessed the North American species attributed to the genus, and determined only two as accepted namely H. corsoni & H. majusculus. The remaining species were identified as either junior synonyms, moved to other genera or considered nomen dubium do to incomplete fossils.[4]
| Hadrianus | |
|---|---|
 | |
| Hadrianus majusculus | |
Scientific classification  | |
| Domain: | Eukaryota |
| Kingdom: | Animalia |
| Phylum: | Chordata |
| Class: | Reptilia |
| Order: | Testudines |
| Suborder: | Cryptodira |
| Clade: | Pantestudinoidea |
| Superfamily: | Testudinoidea |
| (unranked): | †Pantestudinidae |
| Genus: | †Hadrianus Cope, 1872[2][1] |
| Species | |
| |
Taxonomy
- Hadrianus corsoni (Leidy, 1871)
- Synonyms Emys carteri Leidy, 1871; Testudo hadriana Cope, 1871; Hadrianus quadratus Cope, 1871; Hadrianus octonaria Cope, 1871; Hadrianus tumidus Hay 1908; Hadrianus robustus Gilmore, 1915; Hadrianus utahensis Gilmore, 1915; Geochelone gilmorei Auffenberg, 1974
- Hadrianus majusculus Hay, 1904
Nomen dubium
- "Hadrianus allabiatus" Cope, 1871
Moved species
- "Hadrianus schucherti" Hay, 1899 moved to Cymatholcus schucherti (Hay, 1899)