AUSTRALIAN MUSEUM SCIENTIFIC PUBLICATIONS Mengden, G. A., 1983. The taxonomy of Australian elapid snakes: a review. Records of the Australian Museum 35(5): 195–222. [30 December 1983]. doi:10.3853/j.0067-1975.35.1983.318 ISSN 0067-1975 Published by the Australian Museum, Sydney naturenature cultureculture discover discover AustralianAustralian Museum Museum science science is is freely freely accessible accessible online online at at www.australianmuseum.net.au/publications/www.australianmuseum.net.au/publications/ 66 CollegeCollege Street,Street, SydneySydney NSWNSW 2010,2010, AustraliaAustralia Records of the Australian Museum (1983) Vol. 35: 195-222. ISSN-0067-1975 195 The Taxonomy of Australian Elapid Snakes: A Review GREGORY A. MENGDEN Population Biology, Research School of Biological Sciences, The Australian National University, Canberra, A.C.T. 2600* ABSTRACT. Published data on Australian elapid snake taxonomy are reviewed. Both classical morphological studies and relevant ecological, chromosomal and biochemical data are summarized. Attention is focused on two major areas: (1) the phylogenetic relationships between Australian terrestrial elapids and other protero­ glyphs; and (2) the interrelationships among the Australian terrestrial elapids. From this review four key questions are identified: (1) Are the continentally endemic groups of terrestrial elapids confamilial? (2) Do the Australian elapids represent a distinct familial group? (3) Are the Australian elapids monophyletic or have the extant forms been derived from distinct lineages which may represent more than one invasion of the continent? (4) What is the precise relationship between laticaudine and hydrophiine sea snakes and the Australian elapids? There is considerable disagreement concerning generic allocations and suprageneric relationships within the Australian proteroglyphs. Ecological, cytological and biochemical studies currently under way may be useful adjuncts to morphological information in resolving these questions. MENGDEN, GREGORY A., 1983. The taxonomy of Australian elapid snakes: a review. Records of the Australian Museum 35(5): 195-222. CONTENTS Abstract .................................................... 0 • • • • • •• 195 Introduction ........................................................ 196 I. A BACKGROUND TO ELAPID CLASSIFICATION ................. 196 1. The Origins and Affinities of Terrestrial Proteroglyphs ............. 196 l(a) The morphological data .................................... 0 196 l(b) The biochemical data .................................... 0" 197 l(c) Dendroaspis-A distinctive elapid? ........................... 198 2. The Origins and Affinities of the Marine Proteroglyphs ......... 0 ••• 198 2(a) The morphological data ..................................... 198 2(b) The biochemical data ....................................... 199 2(c) The chromosomal data ............................... 0 •••••• 199 3. A Summary of Proteroglyph Relationships ........................ 200 *Present Address: Herpetoiogy Department, Australian Museum, P.O. Box A285, Sydney South, N.S.W. 2000. 196 Records of the Australian Museum (1983), Vol. 35 n. TAXONOMIC RELATIONSHIPS WITHIN THE AUSTRALIAN TERRESTRIAL ELAPIDS ........................................ 200 1. The Classifications since Giinther (1858) .......................... 200 2. The Morphological Data ........................................ 201 2(a) Taxonomic changes to Boulenger's Denisonia .................. 201 2(b) Taxonomic changes to Boulenger's Diemenia (Demansia) ....... 202 2(c) Taxonomic changes to Pseudelaps, Furina and G/yphodon ...... 202 2(d) Taxonomic changes to Vermicella and Simoselaps .............. 203 2(e) Additional taxonomic changes to Australian elapids ............ 203 2(D The intergeneric relationships proposed by McDowell ........... 204 3. The Biochemical Data .......................................... 204 4. A Summary of the Taxonomic Relationships of Australian Terrestrial Elapids ............................................ 205 5. Concluding Remarks ............................................ 205 Acknowledgements .................................................. 205 The combined proteroglyphous or fixed-front-fanged 1973), the incomplete nature of most of the fossil forms, snakes are represented world-wide by approximately 63 and consequent difficulty of recognizing primitive and genera and 245 species (Elapidae, Laticaudidae and derived character states in them (Dowling & Duellman, Hydrophiidae of some authors). Of these, 16 genera and 1978; see also Schwaner & Dessauer, 1982). 53 species are marine forms. This group contains a large Storr (1964) pointed out that the Elapidae (pre­ percentage of those venomous snake species dangerous sumably referring to all terrestrial proteroglyphs) give to man. the appearance of an "old declining group". He also This report summarizes the published classifications commented that, with the exception of Naja (true on the Australian elapids, including those based on cobras), all the forty or so then recognized genera morphological criteria as well as the recent biochemical formed distinct geographic groups endemic to particular and cytological work that has obvious taxonomic continents. implications. The aim of this review is to clarify the The terrestrial elapids are generally considered to problems still to be resolved in elapid taxonomy and have been derived from a colubrid ancestor. The marine provide a taxonomic baseline for future contributions. proteroglyphs are assumed either to have been derived This paper provides a summary of previous taxonomic directly from terrestrial elapid snakes or else to share studies, but does not suggest any new taxonomic a common ancestral stock with them (see Cogger, 1975a designations. Nor do I wish to offer a reassessment of for summary). Indeed their close affinities were characters. Consequently, I have avoided weighting indicated by Underwood (1967), who gave them characters or biasing the presentation toward anyone con familial status with a single division between all of the classifications that have been published. The terrestrial (subfamily Elapinae) and marine (subfamily paper deals first with the question of relationships Hydrophiinae) forms (Table 1). This was subsequently among proteroglyphous snakes world-wide, and then supported by Hardaway & Williams (1976) following focuses on relationships among the Australian terrestrial an analysis of the costal cartilages of the ribs and proteroglyphs. modified by Underwood (1979) to include subfamily Laticaudinae. Dowling (1967) also placed all proteroglyphs in the family Elapidae but divided the family into four subfamilies: Apisthocalaminae ("stem elapids"), Elapinae ("terrestrial elapids"), Laticaudinae I. A BACKGROUND TO "ELAPID" ("recent sea snakes"), and Hydrophiinae ("advanced CLASSIFICATION sea snakes"). Table 1 lists all genera of proteroglyphs, their 1. The Origins and Affinities of the common names and some relevant taxonomic comments Terrestrial Proteroglyphs from the literature. The sparse fossil record of elapids commences in the l(a). The Morphological Data upper Miocene in France and Morocco (Hoffstetter, Doubt was cast on the monophyletic origin of the 1962). This rccord, however, has been of little help in proteroglyph condition by the work of Bourgeois (1965) determining precise categories of snake taxa owing to on the African Mole Viper (Atractaspis) and that of the lack of critical fossils (Dowling, 1959; Marx & Rabb, McDowell (1968) on the African elapid snake Elaps ( = MENGDEN: Taxonomy of Australian elapid snakes 197 Homorelaps sensu Boulenger 1896 = Homoroselaps as Maticora and the sea kraits Laticauda. McDowell's per opinion 1201 of Int. Comm. Zoo!. Nomenclature, classification was adopted by Smith et al. (1977) and 1982). Both authors attempted to demonstrate that the three tribes within the subfamily Elapinae were erected: closest affinities of their respective forms lay with the the Elapini (= American and North Asian coral snakes), same group of rear-fanged (opisthoglyphous) African the Maticorini (= South Asiatic coral snakes) and colubrids. This would mean that the two separate venom Laticaudini (= sea kraits). delivery systems of the Viperidae (solenoglyphous [movable-front-fanged] snakes), to which Atractaspis l(b). The Biochemical Data (Terrestrial Proteroglyphs) then belonged, and the Elapidae (proteroglyphous Turning to the chemotaxonomic data, the immuno­ [fixed-front-fanged] snakes), to which Elaps then logical study of Cadle & Sarich (1981) refuted the belonged, would have arisen in parallel from a classification proposed by Savitsky (1978) and Duellman somewhat similar ancestral stock. In the most recent (1979). Using micro complement fixation analysis summaries of snake classification (Smith et al., 1977; (M C' F) Cadle and Sarich (1981) demonstrated a closer Underwood, 1979; Harding & Welch, 1980), which relationship between the micrurines, the Asian elapids relied heavily on the morphological work of McDowell, Ophiophagus and Bungarus, the Australian elapid Atractaspis has been accorded the status of a separate Austrelaps and the sea kraits Laticauda, on the one subfamily (Atractaspinae) within the family Colubridae, hand, than between the micrurines and any of the though Branch (1981) suggested that tribal designation xenodontine colubrids or hydrophiine sea snakes on the within the subfamily Aparallactinae may more other. They claimed that their data unequivocally placed