The blunt-toothed giant hutia (''Amblyrhiza inundata'') is an extinct species of

giant hutia Heptaxodontidae, rarely called giant hutia, is an extinct family of large rodents known from fossil and subfossil material found in the West Indies. One species, ''Amblyrhiza inundata'', is estimated to have weighed between , reaching the weight ...

from

Anguilla Anguilla ( ) is a British Overseas Territory in the Caribbean. It is one of the most northerly of the Leeward Islands in the Lesser Antilles, lying east of Puerto Rico and the Virgin Islands and directly north of Saint Martin. The territo ...

and Saint Martin that is estimated to have weighed between 50 and 200 kg (110 and 440 lb). It was discovered by

Edward Drinker Cope Edward Drinker Cope (July 28, 1840 – April 12, 1897) was an American zoologist, paleontologist, comparative anatomist, herpetologist, and ichthyologist. Born to a wealthy Quaker family, Cope distinguished himself as a child prodigy interested ...

in 1868 in a sample of phosphate sediments mined in an unknown cave (possibly Cavannagh Cave) in Anguilla and sent to Philadelphia to estimate the value of the sediments. It is the sole species of the genus ''Amblyrhiza'' in the fossil family

Heptaxodontidae Heptaxodontidae, rarely called giant hutia, is an extinct family of large rodents known from fossil and subfossil material found in the West Indies. One species, ''Amblyrhiza inundata'', is estimated to have weighed between , reaching the weight ...

. Some authors have suggested that its extinction may have resulted from overhunting by pre-Columbian humans. However, it is unknown whether this species was contemporaneous with human populations. Fossil specimens discovered at the end of the 20th century on Anguilla have been dated to the last interstadial period, while very recent discoveries made on Coco Islet ( Saint-Barthélemy) are dated to 400,000 - 500,000 years; no bone has been recovered yet from a pre-Columbian archaeological site. Despite being described as a "giant

hutia Hutias (known in Spanish as jutía) are moderately large cavy-like rodents of the subfamily Capromyinae that inhabit the Caribbean islands, with most species restricted to Cuba and Hispaniola. Twenty species of hutia have been identified, but at ...

", it has recently been recovered as a member of the

Chinchilloidea Caviomorpha is the rodent infraorder or parvorder that unites all New World hystricognaths. It is supported by both fossil and molecular evidence. The Caviomorpha was for a time considered to be a separate order outside the Rodentia, but is now ...

Description

Paleontologist A. R. Biknevicius and his team have estimated body size for ''Amblyrhiza inundata'' based upon 5 femora and 9 humeri from adult ''Amblyrhiza'' remains. They concluded based upon these specimens that ''Amblyrhiza'' ranged from just under 50 kg in mass to over 200 kg in mass. These calculations were based on comparisons with extant caviomorphs of 16 different species. The blunt teeth of ''Amblyrhiza inundata'' suggest an herbivorous lifestyle, consistent with that of the other genera within Heptaxodontidae.

Taxonomy

Known colloquially as the “Blunt Toothed Hutia,” this animal's scientific name reflects a similar narrative. “''Amblyrhiza''” roughly translates to “blunt root,” and “''inundata''” has been speculated to be in reference to Cope's disbelief that such a large rodent could evolve in an isolated region such as the islands of the northern Lesser Antilles. It is now accepted that Cope thought that the animal was cosmopolitan in nature, moving freely from island to island due to the lowered sea levels of the interval, which enabled ''Amblyrhiza'' to develop such an impressive body size. ''Amblyrhiza'' is currently considered to be a close relative of ''Elasmodontomys obliquus'', a smaller yet similar rodent found in the Quaternary deposits of Puerto Rico. Although it has yet to be decided exactly where ''Amblyrhiza'' fits in a phylogenetic context, it is thought that they belong to a paraphyletic group of giant caviomorphs known as Heptaxodontidae. More recent work finds ''Amblyrhiza'' and ''Elasmodontomys'' to be members of the Chinchilloidea, with ''Amblyrhiza'' being most closely related to ''

Dinomys The pacarana (''Dinomys branickii'') is a rare and slow-moving hystricognath rodent indigenous to South America. Native Tupi people call it the ''pacarana'' (false paca) because it is superficially similar to the paca, a different rodent which is ...

''.

Discovery

Paleontology work began in the northeastern area of the Caribbean in the mid nineteenth century, when phosphate mining boomed in the region and fossils were coincidentally found in associated strata. Later, in 1868, samples of fossils and their overlying sediments were sent from the islands to the Philadelphia Academy of Sciences to estimate the potential scientific value of said specimens. These fossils were then given to famed paleontologist Edward Drinker Cope, who was serving as the academy's secretary at that time. Cope is said to have taken particular interest in them and their notably large size. The fossilized remains of this remarkably large rodent are found solely within Quaternary cave deposits, all of which are located on the islands of the northern Lesser Antilles, specifically Anguilla and St. Martin.

References

{{Taxonbar, from=Q1768293 Heptaxodontidae Taxa named by Edward Drinker Cope Pleistocene extinctions Fossil taxa described in 1868