A Systematic and Taxonomic Review of Two Australo-Pacific Snake Genera (Elapidae: Oxyuranus and Pseudonaja)

Abstract

This study investigated two protocols for use with taxonomic research and provides a significant step toward a comprehensive taxonomic revision of two Australo-Pacific snake genera: taipans (Elapidae: Oxyuranus) and brown snakes (Elapidae: Pseudonaja). These snakes are of interest to many people for reasons such as the proximity of their distribution to major urban centres, the potential lethality associated with their venom, and the morphological variation found in most sub-taxa. Distributed throughout Australia and parts of Indonesia and Papua New Guinea, taipans and brown snakes are noted both for their morphological variability and sub-taxa similarity. These two reasons are partially why, since the first species of brown snake was erected in 1854, 48 different (sub)species of Oxyuranus and Pseudonaja have been described as valid taxa. A third reason may be methodological: the use of inappropriate sampling techniques and laboratory methods. The present study tested and validated a novel systematic sampling methodology for taxonomic and systematic research, investigated the appropriateness for the inclusion of archival DNA in molecular research, and conducted phylogenetic and morphologic analyses of past and present data collected from these taxa. A review of the taxonomic history of these snakes (presented in Chapter 1) shows that the evolutionary relationships of Oxyuranus and Pseudonaja sub-taxa have long been uncertain. Previous taxonomic and systematic inquiries have been descriptive in nature, inconsistent characters have been selected for analysis, specimen selection has been opportunistic, and molecular studies have been reliant on fresh tissue for genetic analyses. These issues may be, in part, why there is still taxonomic uncertainty regarding the number of valid taxa associated with these snakes. This study attempted to uncover the evolutionary relationships of these snakes using novel and improved techniques. These techniques were first tested for their adequacy, then employed in further experiments designed to resolve Oxyuranus and Pseudonaja taxonomy.