Project 4 - Small Terrestrial Vertebrates: Clarifying Taxonomic Status

4.4: Taxonomy of some of Australia's 'best known' mammals and reptiles

Challenges

Certain groups of Australian mammals and reptiles are not only better studied scientifically but also more familiar to members of the Australian and international community. This is usually because they are large and brightly-patterned, relatively abundant and easily observed, or sometimes just plain 'cute' or 'peculiar'. In considering where to best direct our limited taxonomic effort, these groups can be easily overlooked in favour of more obviously neglected candidates such as small rodents and burrowing reptiles. However, on reflection these groups often turn out to be no better known taxonomically, and no less deserving of attention.

Study of these animals generally poses no special difficulties – just the will to ask that basic question "Are they really all the same?"

Seeking solutions

We will undertake taxonomic studies of several comparatively well-studied and 'iconic' groups of mammals and reptiles in a bid to explore the wider state of knowledge of the Australian terrestrial vertebrate fauna. Our work will include some within-species questions (i.e. "Are they really all the same?") as well as some questions of higher level classification (How should we divide this group of species among genera?).

The primary targets at the basic species level are the greater gliders (Petauroides volans), the Feather-tailed Glider (Acrobates pygmaeus), the marsupial moles (Notoryctes spp.) and the giant white-tailed rat (Uromys caudimaculatus), several members of the skink genus Egernia, and several goannas (Varanus spp.). The primary targets at the higher level of classification are the Australian native rats and mice (especially the genus Pseudomys) and the skink genera Egernia and Tiliqua.

Approaches

For the species level studies we will use an iterative approach that begins with initial screening of mtDNA haplotypes from all available samples of the target groups. Patterns of genetic diversity are then compared with patterns of morphological differentiation, and further molecular investigations carried out (e.g. nuclear gene sequencing, microsats, allozyme electrophoresis), as appropriate to each case.

To resolve the higher classification of target group, we will use a combination of molecular sequencing approaches and cladistic analysis of morphological traits. For the mammal project, we will attempt to include a number of extinct taxa into molecular analyses through extraction and sequencing of DNA derived from historically collected individuals or specimens collected on the surface of cave deposits.

Collaboration

The work on Petauroides involves collaboration with Dr Brian Arbogast (Humbolt State University, California) and Dr Andrea Taylor (Monash University); work on Notoryctes with Dr Joe Benshemesh (SA DEH); work on Uromys with Dr Kris Helgen (US National Museum); work on Egernia and Tiliqua with Dr Paul Doughty and Brad Maryan (Western Australian Museum), Dr Patrick Couper (Queensland Museum) and Ross Sadlier (Australian Museum); and work on Varanus with Mark Adams (South Australian Museum) and Alison Fitch (Flinders University).

Tools for Decision Makers

The work will lead to significant new insights into the patterning of evolutionary diversity among a number of iconic Australian terrestrial vertebrates. The primary means of communication will be through taxonomic publications but results of this work will be made more accessible through provision of web-based resources including interactive keys.