Temporal range: 55.4–33.9 Ma Eocene[1]
"Hadrianus majusculus"
Hadrianus majusculus
Scientific classification Edit this classification
Kingdom: Animalia
Phylum: Chordata
Class: Reptilia
Order: Testudines
Suborder: Cryptodira
Clade: Pantestudinoidea
Superfamily: Testudinoidea
(unranked): Pantestudinidae
Genus: Hadrianus
Cope, 1872[2][1]
  • H. corsoni
  • H. majusculus
  • H. octonaria
  • H. robustus
  • H. schucherti
  • H. utahensis
  • H. vialovi

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]


  1. ^ a b c "Fossilworks: Hadrianus". fossilworks.org. Retrieved 17 December 2021.
  2. ^ E. D. Cope. 1872. Second account of new Vertebrata from the Bridger Eocene. Proceedings of the American Philosophical Society (separate) 1-3
  3. ^ a b c 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.