Toxicocalamus pumehanae O'SHEA, ALLISON & KAISER, 2018
Can you confirm these amateur observations of Toxicocalamus pumehanae?
|Higher Taxa||Elapidae (Hydrophiinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Common Names||E: Managalas Plateau Snake|
|Synonym||Toxicocalamus pumehanae O'SHEA, ALLISON & KAISER 2018|
|Distribution||Papua New Guinea (Oro)|
Type locality: Jarefa Camp village (09°12′ 19′′ S, 148°14′ 15′′ E; fig. 4), elevation 820 m, near Itokama (= Itogama), on the Managalas Plateau, Managalas Conservation Area, Ijvitari District, Oro Province, Papua New Guinea
|Types||Holotype: BPBM 36185 (figs. 2, 3), a juvenile female, collected by Allen Allison in March 2010.|
|Diagnosis||Diagnosis: Toxicocalamus pumehanae is only known from its holotype, a diminutive female specimen measuring 220 mm SVL + 21 mm TL = 241 mm TTL. It can be distinguished from all other Toxicocalamus by the following combination of characters: dorsum of head exhibiting fused prefrontal-internasal scutes but separate and distinct single preoculars (an extremely rare combination in Papuan elapids – see Discussion: Head scute fusion); undivided nasal scutes with small, central, circular nares; rostral as broad as high; paired postoculars; single anterior and paired posterior temporals; broad frontal between supraoculars; elongate paired parietals (fig. 5A′), six supralabials, with the 3rd-4th supralabials contacting the orbit (fig. 5C′ , D′ ); six infralabials with 1st-3rd contacting anterior genials, anterior genials overlapping, mental groove absent, posterior genials separated by two intergenials, anteriormost on midline, posterior to anterior genials; distinctive dark spot present on junction of 3rd-4th infralabials (fig. 5B′); dorsal scales in 15-15-15 rows; 235 ventrals, followed by a pair of precloacal scales (fig. 5E′); paired cloacal scales; 35 subcaudals, all paired; short tail, laterally slightly compressed, terminating in a conical terminal scale (figs. 5F′ , 7A).|
Comparisons: The genus Toxicocalamus can be distinguished from all other terrestrial New Guinea elapid genera, except Pseudonaja, by the absence of a temporolabial scale between the 5th and 6th supralabials (see Discussion). Although Pseudonaja also lacks a temporolabial scale, it is easily distinguished from Toxicocalamus by its large eyes (diameter 1.5 times the distance from the lower edge of the orbit to the margin of the lip), strongly pronounced, protruding supraocular scales, and highly alert and active terrestrial habitus. In contrast Toxicocalamus species possess relatively small eyes (diameter subequal to the distance from the lower edge of the orbit to the margin of the upper lip), supraocular scales that do not protrude laterally above the eyes, and they exhibit a secretive, semi-fossorial to terrestrial habitus. McDowell (1969) synonymised Toxicocalamus, Apistocalamus, and Ultrocalamus with Toxicocalamus and proposed their status as subgenera. The species in the subgenus Toxicocalamus (T. grandis, T. holopelturus, T. loriae, T. spilolepidotus) exhibit the classic ‘colubrid-elapid nine-scute arrangement’ (sensu O’Shea, 2005: 12), as do three recently described species: T. pachysomus Kraus, 2009, T. ernstmayri O’Shea et al., 2015, and T. nigrescens Kraus, 2017. In contrast, species in the subgenera Apistocalamus (T. longissimus, T. misimae, T. stanleyanus) and Ultrocalamus (T. buergersi, T. preussi) are characterised by some degree of head-scute fusion (table 1) involving fused preocular-prefrontal scutes in Apistocalamus, and fused preocular-prefrontal-internasal scutes in Ultrocalamus. The recently described T. mintoni (Kraus, 2015) and T. cratermontanus (Kraus, 2017) also exhibit fused preocularprefrontal scutes, although the former is unique in the possession of a head-wide mid-dorsal scute comprising the frontal and both supraocular scutes. Toxicocalamus pumehamae exhibits head scute fusion but does not feature any of the hitherto seen Toxicocalamus arrangements. We here compare T. pumehanae with fifteen congeners (fourteen species and one subspecies), with relevant characteristics for these species presented in parentheses. We also present a listing of these comparative characters, expanded from the version in O’Shea et al. (2015) to include T. pumehanae and the recently described T. nigrescens and T. cratermontanus (table 2). Toxicocalamus pumehanae exhibits fusion of the prefrontal and internasal scutes (figs. 5A′, 8A) that distinguishes it from those species that exhibit the regular ‘colubridelapid nine-scute dorsal arrangement’ (T. ernstmayri, T. grandis, T. holopelturus, T. loriae,9 T. nigrescens, T. pachysomus, T. spilolepidotus). Fusion of the prefrontal and internasal scutes without involvement of the preocular scale distinguishes T. pumehanae (figs. 5A′, C′, D′, 6A) from T. cratermontanus, T. longissimus, T. misimae, T. stanleyanus, and T. mintoni (fig. 6E-H, fused prefrontal-preocular scutes, but distinct and separate internasal scutes), and from T. buergersi, T. p. preussi, and T. p. angusticinctus (fig. 6B-D, fused preocular-prefrontalinternasal scutes). Toxicocalamus mintoni further exhibits a broad, head-wide, mid-dorsal scute derived from the fusion of the frontal scute with its neighbouring supraocular scutes (fig. 6E), a character not seen in any other terrestrial elapid, and possibly unique amongst colubroid snakes. The presence of six supralabials separates T. pumehanae from T. p. preussi, T. p. angusticinctus, and T. stanleyanus (fig. 6C-D, G, five supralabials), and T. buergersi (fig. 6B, four supralabials). Toxicocalamus pumehanae exhibits a dorsal scale count of 15-15-15 that distinguishes it from T. p. preussi, T. p. angusticinctus (both 13-13-13), and T. longissimus (17-17-17), while the paired cloacal scales separate it from T. buergersi, T. cratermontanus, T. preussi, T. stanleyanus, and some Oro Province T. loriae sensu lato11 (single cloacal scale), and the mostly paired subcaudal scales separate it from T. holopelturus (all subcaudals single). However, the regularly formed and paired precloacal scales (fig. 5E′) present in the holotype of T. pumehanae appear to be a unique character within the genus Toxicocalamus, distinguishing it from all other known species, although occasional specimens of T. loriae also exhibit irregular, partially or completely paired terminal ventral scutes.
|Etymology||The species name pumehanae is a matronym honouring Kathleen Imada, whose Hawaiian name is Pumehana and who was a collection technician in the Vertebrate Zoology Collection at the Bernice P. Bishop Museum in Honolulu, Hawaii, USA. She was instrumental in the development of the Museum’s herpetology collections database and the scientific success of the collection over more than a decade of service. She now works in the Museum’s Botany Collection. Most relevant to this paper and this new species is that Pumehana facilitated the visit by MOS to the collection in June 2014 so that he could examine New Guinea elapids; she also arranged a loan of 16 specimens, including the holotype, for further study at the University of Wolverhampton (United Kingdom), in late 2014.|