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 ...
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 ...
rodent
Rodents (from Latin , 'to gnaw') are mammals of the Order (biology), order Rodentia ( ), which are characterized by a single pair of continuously growing incisors in each of the upper and Mandible, lower jaws. About 40% of all mammal specie ...
from the
Canary Islands
The Canary Islands (; ) or Canaries are an archipelago in the Atlantic Ocean and the southernmost Autonomous communities of Spain, Autonomous Community of Spain. They are located in the northwest of Africa, with the closest point to the cont ...
,
Spain
Spain, or the Kingdom of Spain, is a country in Southern Europe, Southern and Western Europe with territories in North Africa. Featuring the Punta de Tarifa, southernmost point of continental Europe, it is the largest country in Southern Eur ...
. It is the only
species
A species () is often defined as the largest group of organisms in which any two individuals of the appropriate sexes or mating types can produce fertile offspring, typically by sexual reproduction. It is the basic unit of Taxonomy (biology), ...
in the
genus
Genus (; : genera ) is a taxonomic rank above species and below family (taxonomy), family as used in the biological classification of extant taxon, living and fossil organisms as well as Virus classification#ICTV classification, viruses. In bino ...
''Malpaisomys''.
The lava mouse is known from
Holocene
The Holocene () is the current geologic time scale, geological epoch, beginning approximately 11,700 years ago. It follows the Last Glacial Period, which concluded with the Holocene glacial retreat. The Holocene and the preceding Pleistocene to ...
and
Pleistocene
The Pleistocene ( ; referred to colloquially as the ''ice age, Ice Age'') is the geological epoch (geology), epoch that lasted from to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fin ...
deposits in the eastern Canary Islands, including
Fuerteventura
Fuerteventura () is one of the Canary Islands, in the Atlantic Ocean, geographically part of Macaronesia, and politically part of Spain. It is located away from the coast of North Africa. The island was declared a biosphere reserve by UNESCO i ...
,
Lanzarote
Lanzarote (, , ) is a Spanish island, the easternmost of the Canary Islands, off the north coast of Africa and from the Iberian Peninsula.
Covering , Lanzarote is the fourth-largest of the islands in the archipelago. With 163,230 inhabi ...
, and nearby islets. Radiocarbon dates indicate that it became extinct after the European arrival in the archipelago sometime after 1270 AD, probably due to the introduction of
rats
Rats are various medium-sized, long-tailed rodents. Species of rats are found throughout the order Rodentia, but stereotypical rats are found in the genus ''Rattus''. Other rat genera include ''Neotoma'' (pack rats), '' Bandicota'' (bandicoot ...
.
The species is estimated to have a live body mass of around . A study of its skeletal characteristics suggested that the lava mouse lived in fissures opened in the lava fields. The
morphology
Morphology, from the Greek and meaning "study of shape", may refer to:
Disciplines
*Morphology (archaeology), study of the shapes or forms of artifacts
*Morphology (astronomy), study of the shape of astronomical objects such as nebulae, galaxies, ...
of its teeth indicates that it was an
herbivore
A herbivore is an animal anatomically and physiologically evolved to feed on plants, especially upon vascular tissues such as foliage, fruits or seeds, as the main component of its diet. These more broadly also encompass animals that eat ...
.
Its
evolution
Evolution is the change in the heritable Phenotypic trait, characteristics of biological populations over successive generations. It occurs when evolutionary processes such as natural selection and genetic drift act on genetic variation, re ...
ary relationships were unresolved due to its fairly generic morphology. Rodents on islands generally increase in size during the course of their evolution; the lava mouse was fairly small for an insular rodent (some 20 cm in overall length). Thus, it is more likely than not that it evolved from small
Pliocene
The Pliocene ( ; also Pleiocene) is the epoch (geology), epoch in the geologic time scale that extends from 5.33 to 2.58Paraethomys'', '' Occitanomys'', or relatives thereof, than being a later derivative of the Deomyinae. A 2012 genomic study recovered it as a highly divergent lineage within the genus '' Mus sensu lato'' most closely related to '' Coelomys.''
This rodent owes its name ''Malpaisomys'' to the Spanish word ''malpaís'' ("badlands"), denoting the
lava
Lava is molten or partially molten rock (magma) that has been expelled from the interior of a terrestrial planet (such as Earth) or a Natural satellite, moon onto its surface. Lava may be erupted at a volcano or through a Fissure vent, fractu ...
fields where its fossil remains are sometimes found in cavities.