''Hadrianus'' is an extinct

genus Genus ( plural genera ) is a taxonomic rank used in the biological classification of living and fossil organisms as well as viruses. In the hierarchy of biological classification, genus comes above species and below family. In binomial n ...

tortoise Tortoises () are reptiles of the family Testudinidae of the order Testudines (Latin: ''tortoise''). Like other turtles, tortoises have a shell to protect from predation and other threats. The shell in tortoises is generally hard, and like ot ...

belonging to the Testudinidae found in the

United States The United States of America (U.S.A. or USA), commonly known as the United States (U.S. or US) or America, is a country primarily located in North America. It consists of 50 U.S. state, states, a Washington, D.C., federal district, five ma ...

, the Yolomécatl Formation of

Mexico Mexico ( Spanish: México), officially the United Mexican States, is a country in the southern portion of North America. It is bordered to the north by the United States; to the south and west by the Pacific Ocean; to the southeast by Guate ...

, the

Alai Beds The Alai Beds is an Early Eocene (Ypresian, or Bumbanian in the ALMA classification) geologic formation in the Osh Region of southwestern Kyrgyzstan. The formation has provided many fossils of mammals, lizards, turtles and snakes.Kyrgyzstan Kyrgyzstan,, pronounced or the Kyrgyz Republic, is a landlocked country in Central Asia. Kyrgyzstan is bordered by Kazakhstan to the north, Uzbekistan to the west, Tajikistan to the south, and the People's Republic of China to the ea ...

and

Spain , image_flag = Bandera de España.svg , image_coat = Escudo de España (mazonado).svg , national_motto = '' Plus ultra'' ( Latin)(English: "Further Beyond") , national_anthem = (English: "Royal March") , ...

and believed to be the oldest true tortoise known. 2004 "Skeletochronology as a method of aging Oligocene ''Gopherus laticuneus'' and ''Stylemys nebrascensis'', using ''Gopherus polyphemus'' as a modern analog" Thesis, University of Florida. The genus is thought to be closely related to the genus ''

Manouria ''Manouria'' is a genus of tortoises in the family Testudinidae. The genus was erected by John Edward Gray in 1854. Species The following five species are recognized as being valid, two of which are extant, and three of which are extinct: *'' M ...

''. The genus may have evolved in the subtropics of Asia and subsequently migrated to North America and Europe. 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 In binomial nomenclature, a ''nomen dubium'' (Latin for "doubtful name", plural ''nomina dubia'') is a scientific name that is of unknown or doubtful application. Zoology In case of a ''nomen dubium'' it may be impossible to determine whether a s ...

'' do to incomplete fossils.

Taxonomy

*''Hadrianus corsoni'' **Synonyms ''Emys carteri'' ; ''Testudo hadriana'' ; ''Hadrianus quadratus'' ; ''Hadrianus octonaria'' ; ''Hadrianus tumidus'' ; ''Hadrianus robustus'' ; ''Hadrianus utahensis'' ; ''Geochelone gilmorei'' *''Hadrianus majusculus''

''Nomen dubium''

*''"Hadrianus allabiatus"''

Moved species

*''"

Hadrianus schucherti Hadrianus may refer to: People * Hadrian (76–138), Roman emperor * Gaius Fabius Hadrianus, Roman colonial administrator & politician * Pope Adrian (disambiguation) (any of the listed popes) * Hadrianus Junius Hadrianus Junius (1511–1575), also ...

"'' moved to '' Cymatholcus schucherti''

References

Prehistoric life of Europe Hadrianus (genus) Eocene reptiles of North America Prehistoric turtle genera Taxa named by Edward Drinker Cope Extinct turtles {{paleo-turtle-stub