Jump to content

User:Ankylosaur Enthusiast/sandbox3

From Wikipedia, the free encyclopedia

This is an old revision of this page, as edited by Ankylosaur Enthusiast (talk | contribs) at 09:10, 10 July 2024 (→‎Description). The present address (URL) is a permanent link to this revision, which may differ significantly from the current revision.

Ankylosaur Enthusiast/sandbox3
Temporal range: early Miocene, 18.5-17.0 Ma
Scientific classification Edit this classification
Domain: Eukaryota
Kingdom: Animalia
Phylum: Chordata
Class: Mammalia
Infraclass: Marsupialia
Order: Dasyuromorphia
Family: Thylacinidae
Genus: Wabulacinus
Species:
W. ridei
Binomial name
Wabulacinus ridei
Muirhead, 1997

Wabulacinus is an extinct genus of thylacinid marsupial that lived during the early Miocene in northwestern Queensland, Australia. The type and only known species, Wabulacinus ridei, was named in 1997 by Jeanette Muirhead on the basis of two partial skull bones.

History and naming

The holotype of Wabulacinus (QMF16851) was collected from within the early Miocene strata of the “Camel Sputum site” at the Riversleigh World Heritage Area, Queensland. The specimen consists of a right maxillary fragment, with both the first and second molars preserved. An additional specimen (QMF16852) is known from the type locality, which consists of a left dentary fragment with a broken third molar.

In 1997, palaeontologist Jeanette Muirhead described Wabulacinus ridei as a new genus and species of thylacinid based on these fossil remains. The genus name combines the Wanyii word ‘wabula’ (long ago) with the ancient Greek stem word ‘-kynos' (dog). The species name honours David Ride, for their long-term commitment to Australian vertebrate palaeontology.

Description

The infraorbital foramen is fully closed off by the maxilla and positioned in front of the first upper molar. On the first upper molar, stylar cusps B and D are absent. The crushing region of the tooth crown (talon) and the anterolingually facing cusp (protocone) of the upper molar are reduced in size. The crest in front of the apex of the paracone cusp (preparacrista) and the crest in between the paracone and metacone cusps (centrocrista) are subparallel to each other, forming a continuous straight line. Additionally, the upper first molar lacks a furrow for the preceding premolar. The second upper molar has no stylar cusp B and a reduced stylar cusp D. On the lower third molar, the posterolingually facing cusp (entoconid) is absent, while the cusp in between the hypoconid and entoconid is enlarged (hypoconulid). The third molar has a reduced anterolingually facing cusp (metaconid) and lacks space between the dentition of the mandible. Wabulacinus was a small thylacinid, with an estimated weight of 5.3-7.8 kg (11.7-17.2 lbs).

Classification

Muirhead (1997) placed Wabulacinus within the family thylacinidae, and, with a parsimonious tree, recovered it as sister taxon to the genus Thylacinus. In a 2019 study, Rovinsky et al. conducted three separate phylogenetic analyses to determine the interrelationships within thylacinidae. The first analysis was an undated parsimony, which maintained its placement as sister taxon to Thylacinus. However, in the second analysis, a Bayesian model placed it within a polytomy, alongside Tyarrpecinus and Thylacinus macknessi. In the third and final analysis, a tip-dating Bayesian model incorporating morphological and molecular data found it to be within a minor clade containing Thylacinus potens and Tyarrpecinus. Results of the parsimonious tree from Rovisnky et al. (2019) are shown below:

Paleobiology

Due to its simplified tooth structure and elongation of the carnassial blade, it is thought that Wabulacinus may have been hypercarnivorous. In addition, its short dentary suggests that it had a relatively wide, stouty rostrum that was both capable of delivering a more powerful bite and could handle more stress when tackling prey

The remains of Wabulacinus are known from early Miocene strata within the Riversleigh World Heritage Area, which, at the time, would have been covered in open forest or rainforest. It would have shared its environment with at least two other species of thylacinids and four species of thylacoleonids. It likely was able to avoid competition with them due to differences in body mass, locomotion and niche.

References