''Lasiorhinus angustidens'' ("narrow tooth") was a species of

wombat Wombats are short-legged, muscular quadrupedal marsupials of the family Vombatidae that are native to Australia. Living species are about in length with small, stubby tails and weigh between . They are adaptable and habitat tolerant, and are ...

that lived during the

late Pleistocene The Late Pleistocene is an unofficial Age (geology), age in the international geologic timescale in chronostratigraphy, also known as the Upper Pleistocene from a Stratigraphy, stratigraphic perspective. It is intended to be the fourth division ...

epoch to

early Holocene In the geologic time scale, the Greenlandian is the earliest age or lowest stage of the Holocene Epoch or Series, part of the Quaternary. Beginning in 11,650 BP (9701 BCE or 300 HE) and ending with the 8.2-kiloyear event (c. 8200–8300 B ...

(129,000 to 10,000) years ago in

eastern Australia The eastern states of Australia are the states adjoining the east continental coastline of Australia. These are the mainland states of Victoria, New South Wales and Queensland, and the island state of Tasmania. The Australian Capital Territor ...

. It is known from four isolated

mandible In jawed vertebrates, the mandible (from the Latin ''mandibula'', 'for chewing'), lower jaw, or jawbone is a bone that makes up the lowerand typically more mobilecomponent of the mouth (the upper jaw being known as the maxilla). The jawbone i ...

s (lower jaws) and

teeth A tooth (: teeth) is a hard, calcified structure found in the jaws (or mouths) of many vertebrates and used to break down food. Some animals, particularly carnivores and omnivores, also use teeth to help with capturing or wounding prey, tear ...

, all found in

Darling Downs The Darling Downs is a farming region on the western slopes of the Great Dividing Range in southern Queensland, Australia. The Downs are to the west of South East Queensland and are one of the major regions of Queensland. The name was generally ...

, Australia.

Discovery and taxonomy

Fossils of ''L. angustidens'' were first described by English

naturalist Natural history is a domain of inquiry involving organisms, including animals, fungi, and plants, in their natural environment, leaning more towards observational than experimental methods of study. A person who studies natural history is cal ...

Charles Walter De Vis Charles Walter de Vis (9 May 1829 – 30 April 1915)
— Australian Dictionary of Biography was an England, Engli ...

in 1891 as a novel species of the genus '' Phascolomys,'' the name meaning "narrow tooth". He based ''L. angustidens'' on four cotypes, all incomplete mandibles with teeth which had been collected from

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 ...

-aged sediments in Pilton and

Gowrie Gowrie () is a region in central Scotland and one of the original provinces of the Kingdom of Alba. It covered the eastern part of what became Perthshire. It was located to the immediate east of Atholl, and originally included the area aroun ...

caves in

, Australia during the late 1880s. One of these mandibles, QM F2921, was later designated the

lectotype In biology, a type is a particular specimen (or in some cases a group of specimens) of an organism to which the scientific name of that organism is formally associated. In other words, a type is an example that serves to anchor or centralizes ...

. De Vis believed it was a species of ''Phascolomys'' due to the proportions of the first

incisor Incisors (from Latin ''incidere'', "to cut") are the front teeth present in most mammals. They are located in the premaxilla above and on the mandible below. Humans have a total of eight (two on each side, top and bottom). Opossums have 18, wher ...

alveolus Alveolus (; pl. alveoli, adj. alveolar) is a general anatomical term for a concave cavity or pit. Uses in anatomy and zoology * Pulmonary alveolus, an air sac in the lungs ** Alveolar cell or pneumocyte ** Alveolar duct ** Alveolar macrophage * M ...

, shape of the third

premolar The premolars, also called premolar Tooth (human), teeth, or bicuspids, are transitional teeth located between the Canine tooth, canine and Molar (tooth), molar teeth. In humans, there are two premolars per dental terminology#Quadrant, quadrant in ...

, and length of the ectalveolar (near alveolus on the mandible) groove compared to ''Phascolomys mitchelli''. Later analyses demonstrated that ''P. mitchelli'' is a

synonym A synonym is a word, morpheme, or phrase that means precisely or nearly the same as another word, morpheme, or phrase in a given language. For example, in the English language, the words ''begin'', ''start'', ''commence'', and ''initiate'' are a ...

of ''

Vombatus ursinus The common wombat (''Vombatus ursinus''), also known as the bare-nosed wombat, is a marsupial, one of three extant species of wombats and the only one in the genus ''Vombatus''. It has three subspecies: ''Vombatus ursinus hirsutus'', found on the ...

'', leading Australian mammalogists to reexamine the fossils described by De Vis. The species was moved to the genus ''

Lasiorhinus ''Lasiorhinus'' is the genus containing the two extant hairy-nosed wombats, which are found in Australia. The southern hairy-nosed wombat is found in some of the semiarid to arid regions belt from New South Wales southwest to the South Australia ...

'' based on characteristics of the

(lower jaw) and

. It was then hypothesized by paleontologist Lyndall Dawson in a 1981 study that the material of ''L. angustidens'' could be from juvenile individuals of ''

Sedophascolomys ''Sedophascolomys'' is an extinct genus of wombat known from the Pliocene and Pleistocene of Australia. There is a single recognised species, ''S. medius,'' which was formerly placed in the invalid genus ''Phascolomys.'' It was found in the north ...

'' (then ''Phascolomys'') ''medius'', though more material is necessary to prove this.

References

{{Taxonbar, from=Q121222147 Prehistoric vombatiforms Prehistoric mammals of Australia Prehistoric marsupial genera Pleistocene life Fossil taxa described in 1891 Vombatiforms