Taxonomy and conservation of grassland earless dragons: new species and an assessment of the first possible extinction of a reptile on mainland Australia.

Jane Melville,Stephen D Sarre,Anna J Macdonald,Kirilee Chaplin,Bernd Gruber,Mark Hutchinson,Joanna Sumner

doi:10.1098/rsos.190233

Abstract

Taxonomic research is of fundamental importance in conservation management of threatened species, providing an understanding of species diversity on which management plans are based. The grassland earless dragon lizards (Agamidae: Tympanocryptis) of southeastern Australia have long been of conservation concern but there have been ongoing taxonomic uncertainties. We provide a comprehensive taxonomic review of this group, integrating multiple lines of evidence, including phylogeography (mtDNA), phylogenomics (SNPs), external morphology and micro X-ray CT scans. Based on these data we assign the lectotype of T. lineata to the Canberra region, restrict the distribution of T. pinguicolla to Victoria and name two new species: T. osbornei sp. nov. (Cooma) and T. mccartneyi sp. nov. (Bathurst). Our results have significant conservation implications. Of particular concern is T. pinguicolla, with the last confident sighting in 1969, raising the possibility of the first extinction of a reptile on mainland Australia. However, our results are equivocal as to whether T. pinguicolla is extant or extinct, emphasizing the immediate imperative for continued surveys to locate any remaining populations of T. pinguicolla. We also highlight the need for a full revision of conservation management plans for all the grassland earless dragons.

Highlights

The recent proposal to establish a formalized system for the oversight of taxonomic change [1], has generated heated debate over the role and governance of taxonomy for biodiversity conservation
The electronic edition of this article conforms to the requirements of the amended International Code of Zoological Nomenclature (ICZN), and the new names contained are available under that Code from the electronic edition of this article
Visual inspection of Tympanocryptis lineata Lectotype ZMB 740 confirms that, based on morphology, it is a member of the grassland earless dragons (GEDs) of southeastern Australia

Summary

Introduction

The recent proposal to establish a formalized system for the oversight of taxonomic change [1], has generated heated debate over the role and governance of taxonomy for biodiversity conservation. While the proposal has been widely criticized [2], the message that rigorous scientific-based taxonomic research is an essential element in the conservation of species has emerged from the subsequent debate. Such taxonomic research is fundamental to conservation managers and researchers alike, in defining groups that harbour taxonomic uncertainty. The two main causes of undiagnosed complexes is the presence of cryptic species, consisting of phenotypically indistinguishable taxa [4], or a lack of rigorous taxonomic research in the target group [5]. The critical importance of alpha taxonomy in such groups to prevent further biodiversity losses cannot be overemphasized [6]

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Conclusion