Hadrianus

Superregnum: Eukaryota
Cladus: Unikonta
Cladus: Opisthokonta
Cladus: Holozoa
Regnum: Animalia
Subregnum: Eumetazoa
Cladus: Bilateria
Cladus: Nephrozoa
Superphylum: Deuterostomia
Phylum: Chordata
Subphylum: Vertebrata
Infraphylum: Gnathostomata
Megaclassis: Osteichthyes
Cladus: Sarcopterygii
Cladus: Rhipidistia
Cladus: Tetrapodomorpha
Cladus: Eotetrapodiformes
Cladus: Elpistostegalia
Superclassis: Tetrapoda
Cladus: Reptiliomorpha
Cladus: Amniota
Classis: Reptilia
Cladus: Eureptilia
Cladus: Romeriida
Subclassis: Diapsida
Cladus: Sauria
Cladus: Archelosauria
Division: Pan-Testudines
Division: Testudinata
Ordo: Testudines
Subordo: Cryptodira
Superfamilia: Testudinoidea

Familia: Testudinidae
Genus: †Hadrianus
Species: H. carsoni - H. majusculus

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]
References

"Fossilworks: Hadrianus". fossilworks.org. Retrieved 17 December 2021.
E. D. Cope. 1872. Second account of new Vertebrata from the Bridger Eocene. Proceedings of the American Philosophical Society (separate) 1-3
Ehret, Dana Joseph 2004 "Skeletochronology as a method of aging Oligocene Gopherus laticuneus and Stylemys nebrascensis, using Gopherus polyphemus as a modern analog" Thesis, University of Florida.