Nelson's small-eared shrew (''Cryptotis nelsoni'') is a species of

mammal Mammals () are a group of vertebrate animals constituting the class Mammalia (), characterized by the presence of mammary glands which in females produce milk for feeding (nursing) their young, a neocortex (a region of the brain), fur or ...

in the family Soricidae. It is

endemic Endemism is the state of a species being found in a single defined geographic location, such as an island, state, nation, country or other defined zone; organisms that are indigenous to a place are not endemic to it if they are also found elsew ...

to eastern

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 Guatema ...

. The species was discovered by

Edward William Nelson Edward William Nelson (May 8, 1855 – May 19, 1934) was an American naturalist and ethnologist. A collector of specimens and field naturalist of repute, he became a member of several expeditions to survey the fauna and flora. He was part o ...

and Edward Alphonso Goldman in 1894, who collected a number of specimens from the slopes of the San Martín volcano in

Veracruz Veracruz (), formally Veracruz de Ignacio de la Llave (), officially the Free and Sovereign State of Veracruz de Ignacio de la Llave ( es, Estado Libre y Soberano de Veracruz de Ignacio de la Llave), is one of the 31 states which, along with Me ...

, Mexico. The species was then not recorded again, and thought by many to be extinct, until being rediscovered in the same area in 2004 (as described in 2009). Its biology is essentially unknown. The Nelson's Small-Eared Shrew is considered to be one of the world's 100 most threatened species on the planet. Once thought

extinct Extinction is the termination of a kind of organism or of a group of kinds (taxon), usually a species. The moment of extinction is generally considered to be the death of the last individual of the species, although the capacity to breed and ...

, they have been recently rediscovered in very small numbers. They live in high altitudes on the side of an inactive

volcano A volcano is a rupture in the crust of a planetary-mass object, such as Earth, that allows hot lava, volcanic ash, and gases to escape from a magma chamber below the surface. On Earth, volcanoes are most often found where tectonic plates are ...

. The shrews are tiny (only 10 centimetres long) with brown fur.

References

{{Taxonbar, from=Q1764634 Cryptotis Endemic mammals of Mexico Shrew, Nelsons small-eared Natural history of Veracruz Critically endangered biota of Mexico Critically endangered fauna of North America Mammals described in 1895 Taxa named by Clinton Hart Merriam