Neobatrachus sudelli (Lamb, 1911)

Tyler, Michael J. & Prideaux, Gavin J., 2016, Early to middle Pleistocene occurrences of Litoria, Neobatrachus and Pseudophryne (Anura) from the Nullarbor Plain, Australia: first frogs from the “ frog-free zone ”, Memoirs of Museum Victoria 74, pp. 403-408 : 405-407

Neobatrachus sudelli (Lamb, 1911)

Referred specimens. Leaena’s Breath Cave, ilia: WAM 09.3.260, WAM 09.3.268 (unit 1); WAM 09.3.262, WAM 09.3.272 (unit 2); WAM 09.3.261, WAM 09.3.263, WAM 09.3.265, WAM 09.3.267, WAM 09.3.269, WAM 09.3.270, WAM 09.3.271, WAM 09.3.273, WAM 09.3.276 (unit 3).

Locality. The referred specimens originated from infill sedimentary units 1–3 within the main chamber of Leaena’s Breath Cave, Nullarbor Plain, southeastern Western Australia ( fig. 1 ; table 1). Units 1–2 are of normal magnetic polarity (Brunhes Normal Chron) and are capped in places by speleothem samples dated to ca 400,000 years, so are middle Pleistocene in age ( Prideaux et al., 2007). This falls within the Naracoortean land mammal age ( Megirian et al., 2010). Unit 3 is of early Pleistocene age.

Remarks. The specimens are identified as representing a species of Neobatrachus because they possess a very large and irregularly-shaped dorsal prominence, which varies markedly intraspecifically within this genus ( figs. 3E–H ; Tyler, 1976, 1985). Congeners are distinguished by differences in the height of the dorsal protuberance of the ilium, its shape, and its position on the ilial shaft. In WAM 09.3.260 the dorsal prominence bears an elongated and shallow vertical incision, a well-developed pre-acetabular zone and a broad anterior border ( fig. 3H ). Such a feature has not been reported in any other anuran ilium. The superior acetabular expansion inclines at approximately 45° to the ilial shaft. With this exception, the features expressed by this specimen and each of the Nullarbor Neobatrachus ilia fall within the range of variation expressed by extant specimens of N. sudelli , into which N. centralis has now been synonymised ( Roberts, 2010).

Pseudophryne Fitzinger, 1843

Figures

Figure 1. Map of Australia showing modern occurrence records extracted from the Atlas of Living Australia (www.ala.org.au) and location of Leaena’s Breath Cave (black triangle). a) Anura. b) Neobatrachus sudelli. Note that the two most northwestern records may represent N. aquilonius (J. D. Roberts, pers. comm., 27 June 2015). c) Pseudophryne guentheri (light green) and P. occidentalis (dark green). d) Litoria adelaidensis (red), L. cyclorhyncha (purple) and L. moorei (light brown).

Figure 3. Pleistocene frog ilia from Leaena’s Breath Cave (prefix WAM) compared with modern specimens (prefix SAMA). a) WAM 09.3.264. Right ilium of holotype of Litoria lundeliusi sp. nov. from Leaena’s Breath Cave (unit 3). b) WAM 09.3.264. Enlargement of acetabular region of holotype of Litoria lundeliusi sp. nov. c) SAMA R68398. Representative left ilium of Litoria adelaidensis. d) SAMA R68399. Representative right ilium of Litoria rubella sensu stricto. e–h) Representative ilia of Neobatrachus sudelli highlighting extreme divergence in the form of the dorsal prominence. e) WAM 09.3.265. f) WAM 09.3.261. g) WAM 09.3.269. h) WAM 09.3.273. i) Right ilium of Pseudophryne sp. indet.