Thylacoleo hilli

Thylacoleo hilli lived during the Pliocene and was half the size of Thylacoleo crassidentatus.

Thylacoleo hilli
Temporal range: Pliocene
↓
Scientific classification
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Diprotodontia
Family: †Thylacoleonidae
Genus: †Thylacoleo
Species:
†T. hilli
Binomial name
†Thylacoleo hilli
Pledge, 1977[1]

A holotype fossil was found in Town Cave in South Australia. Additional, possible specimens have been found at the Bow fossil site by students and staff of the University of New South Wales in 1979.

Taxonomy

A fossil species described by Neville Pledge in a study published in the records of the South Australia Museum in 1977. The holotype is a third premolar, discovered at a cave in Curramulka in South Australia, exhibiting the carnivorous characteristics of the genus and around half the size of Thylacoleo carnifex. This tooth was collected by Alan Hill, a speleologist and founding member of the Cave Exploration Group of South Australia, while examining a site known as the "Town Cave" in 1956; the specific epithet hilli honours the collector of the first specimen.[1]

Description

The smallest and most ancient species of Thylacoleo,[1] a genus of three species referred to as "marsupial lions" for the resemblance in form and habits of African lions and distantly related to the modern Thylacinus cynocephalus. They are the earliest species of the genus, appearing in records dating to the Pliocene epoch, and existed at the same time as the larger Thylacoleo crassidentatus.[2]

Unlike other of the family, such as well preserved Thylacinus carfinex fossil and subfossil material, T. hilli is represented by a few fragmentary fossil specimens. The possibility that the small premolar of the species may be a deciduous tooth of another, which are sometimes lost or reabsorbed in some genera of Vombatiformes, was excluded by evidence of wear and lack of this feature appearing in other thylacinid species.[3]

Distribution

The tooth examined by Pledge in 1977 was obtained at vertical shaft in limestone formations on the Yorke Peninsula in South Australia in 1956. The cave had been subject to early excavations for the local supply of water, and in previous investigations had produced specimens of a diprotodont and skeleton of another species of the genus, Thylacoleo carnifex.[1] The placement of the premolar is not associated with other Curramulka fossil fauna, although it is suggested to have been deposited during the Pliocene or an earlier period.[3] Material found amidst the fauna at Bow River in New South Wales, dated to the early Pliocene, was also referred to the species in 1982.[4] A fragment of an incisor, unworn and only diagnosable to the genus, was located at a site in Curramulka, close to the Town Cave site, and referred to the species for the apparent correlation in size when compared to the better known T. carnifex.[5]

Thylacoleo hilli was a similar size to a contemporaneous thylacinid species, Wakaleo alcootaensis, and may have occupied habitat to the exclusion of that carnivore.[6]

References
  1. Pledge, N.S. (1977). "A new species of Thylacoleo (Marsupialia: Thylacoleonidae) with notes on the occurrences and distribution of Thylacoleonidae in South Australia". Records of the South Australian Museum. 17: 277–283.
  2. Mace, Bernard (2001). "Frederick McCoy - the Challenge of Interpretation of Thylacoleonid Fossil Material". The Victorian Naturalist. Field Naturalists Club of Victoria. 118 (6): 287–293.
  3. Hocknull, S.A. (2005). "Ecological succession during the late Cainozoic of central eastern Queensland: Extinction of a diverse rainforest community". Memoirs of the Queensland Museum. 51 (1): 39–122.
  4. Flannery, T.F.; Archer, M. (1984). "The macropodoids (Marsupialia) of the Early Pliocene Bow local fauna, central eastern New South Wales". The Australian Zoologist. 21: 357–383.
  5. Pledge, Neville S. (1992). "The Curramulka local fauna: A new late Tertiary fossil assemblage from Yorke Peninsula, South Australia". The Beagle : occasional papers of the Northern Territory Museum of Arts and Sciences. 9: 115–142.
  6. Murray, P.; Megirian, D. (1990). "Further observations on the morphology of Wakaleo vanderleueri (Marsupialia:Thylacoleonidae) from the mid-Miocene Camfield beds, Northern Territory". The Beagle : occasional papers of the Northern Territory Museum of Arts and Sciences. 7 (1): 91–102.
This article is issued from Wikipedia. The text is licensed under Creative Commons - Attribution - Sharealike. Additional terms may apply for the media files.