''Hesperotestudo'' ("Western turtle") 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 nom ...

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 oth ...

native to North and Central America from the Oligocene to the Late Pleistocene. Species of ''Hesperotesudo'' varied widely in size, with the largest unnamed species from El Salvador reaching in carapace length, larger than that of extant

giant tortoises Giant tortoises are any of various large land tortoises Giant tortoise or giant tortoises may also refer to: * Galápagos giant tortoise, ''Chelonoidis nigra'' are a complex of the largest living species of tortoise. :: Pinta giant tortoise or ...

. Historically considered a subgenus of ''

Geochelone ''Geochelone'' is a genus of tortoises. ''Geochelone'' tortoises, which are also known as typical tortoises or terrestrial turtles, can be found in southern Asia. They primarily eat plants. Species The genus consists of two extant species: A ...

'', it is now considered to be distantly related to that genus. Its closest relatives are the extant ''

Gopherus ''Gopherus'' is a genus of fossorial tortoises commonly referred to as gopher tortoises. The gopher tortoise is grouped with land tortoises that originated 60 million years ago, in North America. A genetic study has shown that their closest relat ...

'' (gopher tortoises) and the extinct '' Stylemys.'' The ancestor of the three genera arrived in North America during the Early

Eocene The Eocene ( ) Epoch is a geological epoch that lasted from about 56 to 33.9 million years ago (mya). It is the second epoch of the Paleogene Period in the modern Cenozoic Era. The name ''Eocene'' comes from the Ancient Greek (''ēṓs'', " ...

. The bodies of ''Hesperotesudo'' species were extensively covered with large dermal ossicles, which in life were covered in keratin. It has been suggested that species of ''Hesperotestudo'' were relatively tolerant of cold weather. ''Hesperotestudo'' became extinct at the end of the Pleistocene and beginning of the

Holocene The Holocene ( ) is the current geological epoch. It began approximately 11,650 cal years Before Present (), after the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene togeth ...

co-incident with the arrival of the first humans in North America, and sites have been found where ''Hesperotestudo'' were butchered.

Taxonomy

Species list is based on Vlachos, 2018 *† ''Hesperotestudo'' Williams 1950Williams , E.E. 1950. ''Testudo cubensis'' and the evolution of Western Hemisphere tortoises. ''Bulletin of the American Museum of Natural History'' 95:1–36. **†''Hesperotestudo bermudae'' Meylan and Sterrer 2000 Bermuda, Middle Pleistocene c. 310,000 years

before present Before Present (BP) years, or "years before present", is a time scale used mainly in archaeology, geology and other scientific disciplines to specify when events occurred relative to the origin of practical radiocarbon dating in the 1950s. Becau ...

(YBP) - shell length c. **†''Hesperotestudo crassiscutata'' (Leidy 1889)Leidy, J. 1889. Description of vertebrate remains from Peace Creek, Florida. ''Transactions of the Wagner Free Institute of Science of Philadelphia'' 2:19–31. Florida, Texas, Illinois, South Carolina, Middle-Late Pleistocene shell length c. **†''Hesperotestudo ducateli'' (Collins and Lynn, 1936)

Calvert Formation The Calvert Formation is a geologic formation in Maryland, Virginia, and Delaware. It preserves fossils dating back to the early to middle Miocene epoch of the Neogene period. The formation is a destination for amateur fossil hunters as well as ...

, Maryland, Middle Miocene (

Langhian The Langhian is, in the International Commission on Stratigraphy, ICS geologic timescale, an age (geology), age or stage (stratigraphy), stage in the middle Miocene epoch (geology), Epoch/series (stratigraphy), Series. It spans the time between 15 ...

–

Serravallian The Serravallian is, in the geologic timescale, an age or a stage in the middle Miocene Epoch/Series, which spans the time between 13.82 Ma and 11.63 Ma (million years ago). The Serravallian follows the Langhian and is followed by the Tortonian ...

) **†''Hesperotestudo gilbertii'' (Hay, 1899) Ogallala Formation, Kansas,

Hemphillian The Hemphillian North American Stage on the geologic timescale is the North American faunal stage according to the North American Land Mammal Ages chronology (NALMA), typically set from 10,300,000 to 4,900,000 years BP. It is usually considered t ...

, Late Miocene-Early Pliocene (

Tortonian The Tortonian is in the geologic time scale an age or stage of the late Miocene that spans the time between 11.608 ± 0.005 Ma and 7.246 ± 0.005 Ma (million years ago). It follows the Serravallian and is followed by the Messinian. The Torto ...

–

Zanclean The Zanclean is the lowest stage or earliest age on the geologic time scale of the Pliocene. It spans the time between 5.332 ± 0.005 Ma (million years ago) and 3.6 ± 0.005 Ma. It is preceded by the Messinian Age of the Miocene Epoch, and ...

) **†''Hesperotestudo orthopygia'' (Cope, 1878) (syn= ''Xerobates cyclopygius'' Cope, 1878 =''Caryoderma snovianum'' Cope, 1886 = ''Testudo rexroadensis'' Oelrich, 1952 = ''Geochelone nordensis'' Holman, 1973) Kansas, California, Nebraska, Late Miocene-Pliocene shell length c. **†''Hesperotestudo osborniana'' (Hay, 1905)(syn= ''Testudo arenivaga'' Hay, 1906 = ''Testudo farri'' Hay, 1908 = ''Testudo impensa'' Hay, 1908 = ''Testudo orthopygia angusticeps'' Matthew, 1924) Colorado, Nebraska, Montana, Early Miocene-Early Pliocene shell length up to **†''Hesperotestudo turgida'' (Cope, 1892) (syn = ''Testudo incisa'' Hay, 1916a = ''Testudo riggsi'' Hibbard, 1944 = ''Testudo wilsoni'' Milstead, 1956 = ''Geochelone johnstoni'' Auffenberg 1962 = ''Geochelone alleni'' Auffenberg, 1966 = ''Geochelone oelrichi'' Holman, 1972a = ''Geochelone mlynarskii'' Auffenberg, 1988) Florida, Oklahoma, Kansas, Texas, Nebraska, Late Miocene-Late Pleistocene shell length c. **†''Hesperotestudo williamsi'' (Auffenberg, 1964)

Oakville Formation The Oakville Formation is a geologic formation in Texas. It preserves fossils dating back to the Neogene period. See also * List of fossiliferous stratigraphic units in Texas * Paleontology in Texas Paleontology in Texas refers to paleontol ...

, Texas, Early Miocene (

Burdigalian The Burdigalian is, in the geologic timescale, an age or stage in the early Miocene. It spans the time between 20.43 ± 0.05 Ma and 15.97 ± 0.05 Ma (million years ago). Preceded by the Aquitanian, the Burdigalian was the first and longest w ...

) shell length c. Hesperotestudo

References

{{Testudinidae Testudinidae Miocene turtles Pliocene turtles Pleistocene turtles Cenozoic reptiles of North America Prehistoric turtle genera Extinct turtles