A new species and subgenus of Elseya (Testudines: Pleurodira: Chelidae) from New Guinea

Abstract

The New Guinea freshwater turtle, Elseya novaeguineae (senu lato) is a long-term, widespread resident of New Guinea and has been subject to substantial vicariance in one of the most geologically dynamic regions on earth. Thus, it should come as no surprise that the taxonomy of this turtle is poorly resolved. Elseya novaeguineae has long been recognized as a species complex, though which elements of this taxon warrant recognition as separate species has been debated. In this paper, we restrict Elseya novaeguineae to the Birds Head region of New Guinea, west of the Langguru Thrust and Fold Belt; we resurrect from synonymy Elseya schultzei for the populations north of the Central Ranges; and we describe a new species for the populations to the south of the Central Ranges. We revisit the classification of the genus Elseya throughout its range in the light of our work and recently published reports, and erect three subgenera that recognize the three major clades within this genus. Subgenus Elseya is the nominate subgenus, to which we assign Elseya dentata, E. branderhorsti and undescribed E. sp. aff. dentata [Sth Alligator]. Elseya novaeguineae, E. schultzei and our new species are assigned to a new subgenus, Hanwarachelys. Species of northern and eastern Queensland, E. albagula, E. irwini, E. lavarackorum and the fossil taxa E. uberrima and E. nadibajagu, are assigned to subgenus Pelocomastes, resurrected from synonymy.

Comparative phylogeographies of six species of hinged terrapins (Pelusiosspp.) reveal discordant patterns and unexpected differentiation in theP. castaneus/P. chapinicomplex andP. rhodesianus

“…To explore this situation in more detail, divergences of the cyt b gene of both forms of P. rhodesianus can be compared with P. carinatus and all other species of Pelusios (Table ). Uncorrected P distances of this gene, and of other mitochondrial genes, are often used as a yardstick to infer taxonomic differentiation of chelonians (e.g., Engstrom, Shaffer & McCord, ; Fritz et al ., , ; Daniels et al ., ; Ennen et al ., ; Vargas‐Ramírez et al ., ; Kindler et al ., ; Iverson, Le & Ingram, ; Martin et al ., ; Petzold et al ., ; Thomson et al ., ) and other reptiles (Torstrom, Pangle & Swanson, ), in analogy to the widely used DNA barcoding approach (e.g., Hebert, Ratnasingham & de Waard, ). The application of such divergence values is based on the observation that deeply divergent lineages correspond to distinct taxa.…”

A new species of freshwater turtle of the genus Elseya (Testudinata: Pleurodira: Chelidae) from the Northern Territory of Australia

“…Legler (UU) and the senior author (UC) were also examined as part of the study. Names of skull elements follows that of Gaffney (1979), shell terminology follows that of Zangerl (1969) with modifications by Pritchard and Trebbau (1984); Thomson et al (1997); Thomson and Mackness (1999) and Thomson et al (2015). Appendix A of Thomson et al (2015) lists the specimens examined for this study.…”

“…The genus Elseya comprises eight living and two fossil short necked species characterized by keratinous head shields and prominent low rounded temporal tubercles and an alveolar ridge on the maxillary triturating surfaces of the mouth (Boulenger 1889). Three major clades are recognized: the northern Elseya (nominal subgenus Elseya, two species) with type species Elseya dentata, the Queensland Elseya (subgenus Pelocomastes, three living and two fossil species) with type species Elseya uberrima, and the New Guinea stream Elseya (subgenus Hanwarachelys, three species) with type species Elseya novaeguineae, and two other taxa E. schultzii and E. rhodini (Thomson et al 2015). The genus Myuchelys (three or four species depending upon usage/ acceptance of the genus Flaviemys, Le et al 2013;Spinks et al 2015) is similar to Elseya but lacks the alveolar ridge.…”

“…These have been progressively named as Elseya irwini (Cann 1997b), Elseya lavarackorum (White & Archer 1994) (as Emydura lavarackorum, reassigned to Elseya and assigned to the extant form byThomson et al 1997), and E. albagula (Thomson et al 2006). The identity and diagnosis of E. branderhorsti (Ouwens 1914) has recently been clarified Thomson et al 2015) and the species complex known as E. novaeguineae (Meyer 1874) resolved with the resurrection of E. schultzii (Vogt 1911) and the description of E. rhodini (Thomson et al 2015). Elseya dentata (Gray 1863) is restricted to the populations occupying the northern rivers from west Arnhem Land of the Northern Territory to the Fitzroy River of Western Australia.…”

“…Older fossils were also reassigned such as Elseya uberrima (de Vis 1897), demonstrating that this old genus was widely distributed throughout Australia. All these fossil taxa belong to the subgenus Pelocomastes (sensu Thomson et al 2015).…”