''Yingabalanara'' is an extinct mammal from the
Miocene of Australia. Known only from a few teeth, its affinities with other mammal groups remain unresolved.
Description
''Yingabalanara'' is known from two lower right molar teeth.
The chewing surface of the tooth has two overlapping crescent-like cusps (hence the animal's name). Due to the sheer bizarreness of the teeth it's not entirely clear to which normal molar structures these cusps correspond to, being variously interpreted as
talonids,
trigonids or other cusps. The molars are double-rooted, and possess what appears to be a remnant
cingulid.
The overall proportions seem to suggest an animal about the size of a
rat
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 ...
, and the tooth morphology is consistent with
omnivorous habits. However, for obvious reasons the animal's overall appearance and morphology are unknown.
Etymology
''Yingabalanara'' is a
Wanyi
The Waanyi people, also spelt Wanyi, Wanji, or Waanji, are an Aboriginal Australian people from south of the Gulf of Carpentaria in Queensland and the Northern Territory.
Language
The Waanyi language, although earlier thought to be extinct, w ...
word meaning "two
moons", in reference to the mammal's crescent-like cusps. The word is masculine in gender, as befitting the status of the predominantly masculine Australian
lunar deities. The species name is an homage to
Graham Richardson, a "Commonwealth Minister for the Environment and the Arts".
Phylogeny
''Yingabalanaras molars are exceptionally unusual among mammals, rendering its exact relations as controversial. Its bizarre cusps differ radically from the normal conditions seen in
marsupials and
placentals (though there are vague similarities to
phyllostomid bats), and while slightly similar to the teeth of
monotreme
Monotremes () are prototherian mammals of the order Monotremata. They are one of the three groups of living mammals, along with placentals (Eutheria), and marsupials (Metatheria). Monotremes are typified by structural differences in their brain ...
s and other
yinotheres the longer and narrower molars, presence of talonid or trigonid-like cusps and lack of lingual or buccal cingulids still set them well apart. The mammal with the most similar teeth is the
Cretaceous North America
North America is a continent in the Northern Hemisphere and almost entirely within the Western Hemisphere. It is bordered to the north by the Arctic Ocean, to the east by the Atlantic Ocean, to the southeast by South America and the Car ...
n ''
Potamotelses'',
which serves of little indication since it too is of uncertain affinities.
For now, ''Yingabalanara'' is included in its own order, Weirdodonta.
See also
* ''
Yalkaparidon'', a contemporary Australian mammal of also uncertain affinities
References
{{Taxonbar, from=Q21368854
Fossil taxa described in 1990
Riversleigh fauna
Prehistoric mammals of Australia