New craniodental remains of Thylacinus potens (Dasyuromorphia: Thylacinidae), a carnivorous marsupial from the late Miocene Alcoota Local Fauna of central Australia.

Adam M Yates

doi:10.7717/peerj.547

Abstract

New craniodental specimens that are referrable to the thylacinid marsupial, Thylacinus potens, are described from the late Miocene Alcoota Local Fauna of the Northern Territory, Australia. The remains include a largely complete maxilla and dentary, showing for the first time the anterior dentition of the dentary. The new remains indicate that Th. potens was a more variable species than previously recognised. The dentary, in particular, is more gracile, than other specimens referred to this species. A revised apomorphy-based diagnosis of Th. potens that takes this variability into account is presented. A cladistic analysis supports previous analyses that placed Th. potens in a derived position within Thylacinidae, close to the modern Th. cynocephalus. New estimations of body size are made using published regressions of dental measurements of dasyuromorphians as well as by assuming geometric similitude with Th. cynocephalus. All methods produce body mass estimates in excess of 35 kg.

Highlights

The recently extinct ‘Tasmanian tiger’ (Thylacinus cynocephalus) was Australia’s largest surviving mammalian carnivore at the time of European settlement
How to cite this article Yates (2014), New craniodental remains of Thylacinus potens (Dasyuromorphia: Thylacinidae), a carnivorous marsupial from the late Miocene Alcoota Local Fauna of central Australia
Since that time an extensive range of pre-Pleistocene thylacinids have been discovered. These indicate that many of the diagnostic characters proposed by Woodburne are widely distributed among pre-Pleistocene thylacinids and represent plesiomorphic characters that are general for thylacinids

Summary

INTRODUCTION

The recently extinct ‘Tasmanian tiger’ (Thylacinus cynocephalus) was Australia’s largest surviving mammalian carnivore at the time of European settlement It belongs to a family of marsupial carnivores, the Thylacinidae, whose fossil record extends back to the late Oligocene (approximately 24 ma) (Wroe, 2003). The 2013 expedition saw the discovery of the first substantial craniodental remains of this species to be recovered since Woodburne’s initial excavation of the Alcoota Local Fauna in 1962–63 These new specimens expand our knowledge of the anatomy of this species and its range of variation. Was the volume of fossil bone extraordinarily high but the diversity was high with almost all of the known taxa from the Alcoota Local Fauna recovered from an excavated area of less than two square meters Among these specimens are postcranial elements as well as upper and lower jaw bones bearing teeth that are referrable to Th. potens. These are the first substantial craniodental remains of this species to be recovered since Woodburne’s initial excavation of the Alcoota local fauna

METHODS

DISCUSSION

Method

Anterior–posterior length of P3

Findings

22. Shape of M3