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

mammal A mammal () is a vertebrate animal of the Class (biology), class Mammalia (). Mammals are characterised by the presence of milk-producing mammary glands for feeding their young, a broad neocortex region of the brain, fur or hair, and three ...

in the family Soricidae. It is

endemic Endemism is the state of a species being found only 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 foun ...

to eastern

Mexico Mexico, officially the United Mexican States, is a country in North America. It is the northernmost country in Latin America, and borders the United States to the north, and Guatemala and Belize to the southeast; while having maritime boundar ...

. 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 Edward Alphonso Goldman (July 7, 1873 – September 2, 1946) was an American field naturalist and mammalogist. He worked extensively in Mexico with Edward William Nelson and described and revised many groups of mammals. He was considered a leading ...

in 1894, who collected a number of specimens from the slopes of the San Martín volcano in the Mexican state of

Veracruz Veracruz, formally Veracruz de Ignacio de la Llave, officially the Free and Sovereign State of Veracruz de Ignacio de la Llave, is one of the 31 states which, along with Mexico City, comprise the 32 Political divisions of Mexico, Federal Entit ...

. 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 an organism by the death of its Endling, last member. A taxon may become Functional extinction, functionally extinct before the death of its last member if it loses the capacity to Reproduction, reproduce 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 commonly defined as a vent or fissure 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 oft ...

. 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