Project 4 - Small Terrestrial Vertebrates: Clarifying Taxonomic Status

4.2: Cryptic diversity in Australian fossorial reptiles

Challenges

Fossorial (burrowing) reptiles often show very simplified body forms, involving reduction or loss of limbs and a bullet-shaped head with simplified scale patterns. This often translates into a small number of characters available for morphological study and a correspondingly reduced capacity to discriminate among species. In addition, many fossorial reptiles were infrequently collected prior to the advent of pit-trapping as a standard survey method, and some remain elusive today. For these reasons, the taxonomy of fossorial reptiles has attracted less attention than other groups of Australian reptiles, and the application of molecular methods to any particular group almost always reveals surprisingly high levels of cryptic diversity.

Seeking solutions

We plan to examine a number of different groups of fossorial reptiles for cryptic diversity, as a means of estimating the degree of taxonomic inadequacy in each group. We will also attempt to resolve the taxonomy of various groups, often working together with local or international collaborators to expedite the work.

Approaches

Our initial screen of genetic diversity will involve sequencing a portion of mtDNA from all available samples of the target groups. Any species that show unusual patterns or excessive levels of genetic diversity are then subject to a rapid morphological examination and further molecular investigations (e.g. nuclear gene sequencing, microsats, allozyme electrophoresis), as appropriate to each case.

Collaboration

The work on blindsnakes is part of an international collaboration with Prof Blair Hedges (Pennsylvania State University) and Dr Nicolas Vidal (Museum Natural Histoire Naturelle, Paris) who have NSF funding to study the taxonomy and evolution of blind snakes and their relatives worldwide. Local collaborators on this project include Dr Mark Hutchinson (South Australian Museum) and Dr Patrick Couper (Queensland Museum).

Tools for Decision Makers

The work will lead to numerous taxonomic publications including an anticipated generic reappraisal of Australian blindsnakes. The results of this work will be made more accessible through provision of web-based resources including interactive keys.