''Prolagus'' is an

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 ...

genus of

pika A pika ( or ; archaically spelled pica) is a small, mountain-dwelling mammal found in Asia and North America. With short limbs, very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but wi ...

within the

order Order, ORDER or Orders may refer to: * Categorization, the process in which ideas and objects are recognized, differentiated, and understood * Heterarchy, a system of organization wherein the elements have the potential to be ranked a number of d ...

Lagomorpha The lagomorphs are the members of the taxonomic order Lagomorpha, of which there are two living families: the Leporidae (hares and rabbits) and the Ochotonidae (pikas). The name of the order is derived from the Ancient Greek ''lagos'' (λαγ� ...

. Over 20 species of ''Prolagus'' have been named, beginning in the

Early Miocene The Early Miocene (also known as Lower Miocene) is a sub-epoch of the Miocene Epoch made up of two stages: the Aquitanian and Burdigalian stages. The sub-epoch lasted from 23.03 ± 0.05 Ma to 15.97 ± 0.05 Ma (million years ago). It was prece ...

Europe Europe is a large peninsula conventionally considered a continent in its own right because of its great physical size and the weight of its history and traditions. Europe is also considered a Continent#Subcontinents, subcontinent of Eurasia ...

20 million years ago, where it ranged widely for most of the epoch; by the end of the Middle Pleistocene, it was confined to a single species, the

Sardinian pika The Sardinian pika (''Prolagus sardus'') is an extinct species of pika that was endemic to the islands of Sardinia, Corsica and neighbouring Mediterranean islands until its extinction likely in Roman times. Unlike living pikas, which all belong t ...

(''P. sardus''), on the

Mediterranean The Mediterranean Sea is a sea connected to the Atlantic Ocean, surrounded by the Mediterranean Basin and almost completely enclosed by land: on the north by Western and Southern Europe and Anatolia, on the south by North Africa, and on the e ...

islands of

Corsica Corsica ( , Upper , Southern ; it, Corsica; ; french: Corse ; lij, Còrsega; sc, Còssiga) is an island in the Mediterranean Sea and one of the 18 regions of France. It is the fourth-largest island in the Mediterranean and lies southeast of ...

Sardinia Sardinia ( ; it, Sardegna, label=Italian, Corsican and Tabarchino ; sc, Sardigna , sdc, Sardhigna; french: Sardaigne; sdn, Saldigna; ca, Sardenya, label=Algherese and Catalan) is the second-largest island in the Mediterranean Sea, after ...

, and surrounding islands, where it survived into historical times. In Africa and Asia, the genus is known from the

Miocene The Miocene ( ) is the first geological epoch of the Neogene Period and extends from about (Ma). The Miocene was named by Scottish geologist Charles Lyell; the name comes from the Greek words (', "less") and (', "new") and means "less recen ...

and

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58scientific name In taxonomy, binomial nomenclature ("two-term naming system"), also called nomenclature ("two-name naming system") or binary nomenclature, is a formal system of naming species of living things by giving each a name composed of two parts, bot ...

may mean "before hares" or "primitive hares" (''pro-'' meaning "before" and ''lagos'' meaning "hare").

Taxonomy

''Prolagus'' was first named by

Auguste Pomel Nicolas Auguste Pomel (20 September 1821 – 2 August 1898) was a French geologist, paleontologist and botanist. He worked as a mines engineer in Algeria and became a specialist in north African vertebrate fossils. He was Senator of Algeria for Ora ...

in 1853. ''Prolagus'' has been considered by most taxonomists to be a member of the pika family Ochotonidae, but distinct from living pikas, which all belong to the genus ''

Ochotona A pika ( or ; archaically spelled pica) is a small, mountain-dwelling mammal found in Asia and North America. With short limbs, very round body, an even coat of fur, and no external tail, they resemble their close relative, the rabbit, but ...

.'' Erbaleva in 1988 suggested it represented the only member of the

monotypic In biology, a monotypic taxon is a taxonomic group (taxon) that contains only one immediately subordinate taxon. A monotypic species is one that does not include subspecies or smaller, infraspecific taxa. In the case of genera, the term "unispec ...

family Prolagidae due to its distinct

dental formula Dentition pertains to the development of teeth and their arrangement in the mouth. In particular, it is the characteristic arrangement, kind, and number of teeth in a given species at a given age. That is, the number, type, and morpho-physiolo ...

; this proposal was considered invalid by

Nieves López Martínez Nieves López Martínez (Burgos, 5 February 1949 - Madrid, 15 December 2010) was a Spanish paleontologist specializing in research on the vertebrate fossil record and part of a group of paleontologists who were responsible for the modernization ...

, due to the fact that many mammal families have lineages with distinct dental formulae. N. López-Martínezbr>Paleobiogeographical history of ''Prolagus'', a European ochotonid (Lagomorpha)
Lynx, 32 (2001), pp. 215-231 However, many authorities such as the

IUCN Red List The International Union for Conservation of Nature (IUCN) Red List of Threatened Species, also known as the IUCN Red List or Red Data Book, founded in 1964, is the world's most comprehensive inventory of the global conservation status of biol ...

and

American Society of Mammalogists The American Society of Mammalogists (ASM) was founded in 1919. Its primary purpose is to encourage the study of mammals, and professions studying them. There are over 4,500 members of this society, and they are primarily professional scientists ...

accept Prolagidae as valid.

Description

''Prolagus'' is distinguished by a continuously growing dentition, a lack of a lower third molar, a trilobed second lower molar and unusually shaped premolars, with additional cusps in the lower third premolar. In comparison to modern pikas of the genus ''Ochotona,'' they have one less

dorsal vertebra In vertebrates, thoracic vertebrae compose the middle segment of the vertebral column, between the cervical vertebrae and the lumbar vertebrae. In humans, there are twelve thoracic vertebrae and they are intermediate in size between the cervical ...

in the spinal column. Most species of ''Prolagus'' probably weighed around 500 g, similar to a living pika. A specimen with preserved soft-tissue is known from late Miocene aged deposits from

Andance Andance (; oc, Andança) is a commune in the Ardèche department in the Auvergne-Rhône-Alpes region of southern France. The inhabitants of the commune are known as ''Andançois'' or ''Andançoises'' Geography Andance is located 5 km so ...

in France, which shows that its overall proportions, shape of the ears and lack of tail are similar to living ''Ochotona.''

Species

Over 20 species of ''Prolagus'' have been named.

Evolutionary history and ecology

''Prolagus'' likely evolved from the

Oligocene The Oligocene ( ) is a geologic epoch of the Paleogene Period and extends from about 33.9 million to 23 million years before the present ( to ). As with other older geologic periods, the rock beds that define the epoch are well identified but the ...

-earliest

genus '' Piezodus.'' The distribution of ''Prolagus'' between 20-8 million years ago extends from the

Iberian Peninsula The Iberian Peninsula (), ** * Aragonese and Occitan: ''Peninsula Iberica'' ** ** * french: Péninsule Ibérique * mwl, Península Eibérica * eu, Iberiar penintsula also known as Iberia, is a peninsula in southwestern Europe, defi ...

in the west to

Anatolia Anatolia, tr, Anadolu Yarımadası), and the Anatolian plateau, also known as Asia Minor, is a large peninsula in Western Asia and the westernmost protrusion of the Asian continent. It constitutes the major part of modern-day Turkey. The re ...

in the east, extending as far north as central Germany, though it was absent from the Italian Peninsula. Early ''Prolagus'' species are thought to have inhabited

subtropical The subtropical zones or subtropics are geographical zone, geographical and Köppen climate classification, climate zones to the Northern Hemisphere, north and Southern Hemisphere, south of the tropics. Geographically part of the Geographical z ...

swamp A swamp is a forested wetland.Keddy, P.A. 2010. Wetland Ecology: Principles and Conservation (2nd edition). Cambridge University Press, Cambridge, UK. 497 p. Swamps are considered to be transition zones because both land and water play a role in ...

and

wetland A wetland is a distinct ecosystem that is flooded or saturated by water, either permanently (for years or decades) or seasonally (for weeks or months). Flooding results in oxygen-free (anoxic) processes prevailing, especially in the soils. The ...

environments, with a similar ecology to the living

marsh rabbit The marsh rabbit (''Sylvilagus palustris'') is a small cottontail rabbit found in marshes and swamps of coastal regions of the Eastern and Southern United States. It is a strong swimmer and found only near regions of water. It is similar in app ...

(''Sylvilagus palustris''). In many European Miocene localities remains of ''Prolagus'' are extraordinarily abundant, and ''Prolagus'' species probably played a key role as prey for many predators. During the late Miocene, ''Prolagus'' dispersed into North Africa due to the connection between Africa and Europe as a result of the

Messinian salinity crisis The Messinian salinity crisis (MSC), also referred to as the Messinian event, and in its latest stage as the Lago Mare event, was a geological event during which the Mediterranean Sea went into a cycle of partial or nearly complete desiccation (dr ...

. The range of ''Prolagus'' shifted southwards and substantially contracted outside of North Africa during the

Pliocene The Pliocene ( ; also Pleiocene) is the epoch in the geologic time scale that extends from 5.333 million to 2.58 ''Prolagus'' first arrived in Corsica, Sardinia, and other Mediterranean islands at the early-late Pliocene boundary, likely due to an emergent land connection. The earliest remains of ''Prolagus'' on the islands are represented by the species ''P. figaro'', ancestral to ''P. sardus.'' Among the last continental species of ''Prolagus'' is ''P. calpensis'' from the Early-Middle

Pleistocene The Pleistocene ( , often referred to as the ''Ice age'') is the geological Epoch (geology), epoch that lasted from about 2,580,000 to 11,700 years ago, spanning the Earth's most recent period of repeated glaciations. Before a change was fina ...

of the

. By the end of the Pleistocene, ''Prolagus'' was confined to Corsica, Sardinia and surrounding islands. The cause of the extinction of the mainland ''Prolagus'' species is not clear, but has been suggested to be due to increased predation pressure.

Notes

References

Additional references of the Paleobiology Database

{{Taxonbar, from=Q511863 Pikas Prehistoric lagomorphs Prehistoric placental genera Miocene genus first appearances Holocene extinctions Fossil taxa described in 1853