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| A, B Toxicocalamus vertebralis sp. nov. from Kol, Jimi Valley, Jiwaka Province, PNG. C, D T. spilorhynchus sp. nov. from Garaina, Morobe Province, PNG. E, F T. atratus sp. nov. from Kundiawa, Wahgi Valley, Chimbu Province, PNG. Kraus, Kaiser & O’Shea, 2022. DOI: 10.3897/vz.72.e89647 Photographs by Fred Parker. |
Abstract
With its conservative set of scalation characters, Toxicocalamus loriae is a morphologically confusing species to which a wide array of phenotypes has been assigned. Careful analysis of 224 museum specimens reveals that multiple distinct species remain hidden under the name T. loriae and that diagnostic, species-level differences are more nuanced in this group of snakes than among other members of the genus. Our taxonomic reassessment leads us to resurrect the species T. lamingtoni comb. nov., T. loennbergii comb. nov., and T. nymani comb. nov. from synonymy with T. loriae, retain only T. pratti as a synonym, and describe three new species. As a consequence, T. loriae is no longer recognized as ranging throughout the entire island of New Guinea but is instead restricted to the southern versant of the Papuan Peninsula, and T. lamingtoni and T. spilorhynchus sp. nov. are species restricted to that same peninsula’s northern versant. Toxicocalamus loennbergii is known only from the type series taken on the Onin Peninsula in West Papua, Indonesia, Toxicocalamus atratus sp. nov. is a high-elevation (800–2200 m) Central Highlands endemic, and T. vertebralis sp. nov. ranges from the Central Highlands of Papua New Guinea eastward into the Wau area of Morobe Province. Toxicocalamus nymani inhabits a geologically more heterogenous region, occurring from the Central Highlands eastward to the Huon Peninsula, including Karkar Island, and adjacent areas of Madang Province as well as the northernmost reaches of the Papuan Peninsula. We expect that denser geographic sampling across New Guinea and focussed specimen collection of a few known populations will result in the recognition of additional species in this complex.
Keywords: Biogeography, Hydrophiinae, morphology, new species, New Guinea, snake, taxonomy
Toxicocalamus loriae (Boulenger, 1898)
Diagnosis: A modestly sized member of the T. loriae Group (maximum SVL in males 490 mm, in females 440 mm) with the following unique combination of characters: two scales covering vent; three infralabials contacting anterior genial; posterior genials separated by two intergenials, one in front of the other; intergenials widest anteriorly. Elongate preocular, at least twice as long as wide, contacting nasal but not internasal; one (in 58% of specimens) or two (42%) postoculars; two (55%) or three (45%) posterior temporals; ventral scale count not sexually dimorphic, 162–197 ventrals in 15 males, 172–190 in four females; subcaudal scale count sexually dimorphic without overlap, 40–50 in males, 28–33 in females; SCR 17.1–21.5% in males, 12.5–16.1% in females; pale markings on prefrontals absent (67%), small or vaguely developed (28%), or present (5%), not obviously correlated with body size; tail spine white, paler than the rest of the tail; venter uniformly yellow, yellow with a mid-ventral row of brown spots on each ventral, with a few brown spots scattered down the venter, or with each spot expanded into a brown bar across the anterior of each ventral.
Etymology: Named by Boulenger (1898) for the collector of the holotype. The description was published in English.
Toxicocalamus nymani (Lönnberg, 1900), comb. nov.
Diagnosis: A modestly sized member of the T. loriae Group (maximum SVL in males 422 mm, in females 540 mm) with the following unique combination of characters: two scales covering vent; three infralabials contacting anterior genial; posterior genials entirely separated (45%) by a single intergenial or in anterior (53%) or entire (2%) contact with each other; intergenial usually widest posteriorly or centrally. Preocular approximately as long as wide and never twice as long as wide, usually contacting nasal (94%), not contacting internasal; one (4%) or two (96%) postoculars; one (1%), two (69%), three (27%), four (1%), or five (1%) posterior temporals; 178–198 ventrals in 18 males, 191–210 in 22 females, sexually dimorphic with overlap (t37 = 4.9581, p < 0.00001); 39–48 subcaudals in males, 26–37 in females, sexually dimorphic without overlap; SCR 17.5–20.7% in males, 11.6–15.8% in females, sexually dimorphic without overlap; yellow nuchal collar and yellow markings on prefrontals absent (48%), small or vaguely developed (7%), or present (45%); tail spine paler than remainder of tail; venter uniformly dark brown or dark brown with the posterior of each ventral paler brown or yellowish brown, giving a banded appearance (reported as “blackish brown, edged with light grey” within one year of preservation; Lönnberg 1900).
Etymology: The species was named for Erik Nyman, the collector of the type series. It also serves as a tribute to a remarkable scientist, who died in 1900 on the journey home to Europe. The description was published in English.
Toxicocalamus loennbergii (Boulenger, 1908), comb. nov.
Diagnosis: A modestly sized member of the T. loriae Group (maximum SVL 565 mm, only females known) with the following unique combination of characters: two scales covering vent; four infralabials contacting anterior genial; a single intergenial separating posterior genials, widest posteriorly. Preocular elongate, approximately twice as long as wide, contacting nasal (62%) or not (38%), not contacting internasal; relatively short snout (SNL/SNW x̄ = 0.95, range = 0.93–0.99); relatively small eye (EY/SNL x̄ = 0.16, range = 0.15–0.18); one postocular (fused to supraocular on one side of one specimen); three posterior temporals; 214–220 ventrals in four females; 23–32 subcaudals; SCR 9.7–12.7%; dark vertebral stripe; large pale blotch on parietal; pale markings on prefrontals absent (50%), small or vaguely developed (25%), or well developed (25%), best developed in the smallest specimen; tail spine white, paler than remainder of tail; and venter uniformly yellow.
Etymology: Named by Boulenger (1908) for Professor Einar Lönnberg (1865–1942), the Swedish zoologist who described Pseudapistocalamus nymani. The description was published in English.
Toxicocalamus lamingtoni (Kinghorn, 1928), comb. nov.
Diagnosis: A modestly sized member of the T. loriae Group (male SVL up to 428 mm, female SVL up to 500 mm), with the following unique combination of characters: cloacal plate single; a single intergenial separating posterior genials, widest posteriorly. Preocular elongate, approximately twice as long as high, contacting nasal but not internasal; one postocular; two (92%) or three (8%) posterior temporals; 160–178 ventrals in nine males, 186–195 in nine females, sexually dimorphic without overlap; 41–53 subcaudals in males, 26–34 in females, sexually dimorphic without overlap; SCR 19.3–23.0% in males, 12.2–14.9% in females, sexually dimorphic without overlap; females with very short tails relative to males (TLR sexually dimorphic without overlap, 16.7–20.8% in adult males, 9.0–11.6% in adult females); pale markings on prefrontals absent, even in juveniles; tail spine brown, same colour as remainder of tail; venter uniformly yellow; juveniles with brown anterior supralabials; and head pattern in juveniles typically consisting of a complete, broad, pale band across the nape, parietals, temporals, and last two supralabials, with remainder of head anterior to that lacking pale markings.
Etymology: Kinghorn (1928: 291) stated that the specimens on which his description was based were all collected in “Mount Lamington district, Northern Division, Papua.” It is possible that the author chose the name of the district, which itself takes its name from Mt. Lamington (8.94°S, 148.16°E, elevation 1680 m), a stratovolcano in Oro Province, Papua New Guinea, as the name for the new species. However, this would ordinarily be indicated by the adjectival suffix -ensis, which Kinghorn did not use. He may have been unaware of proper Latinized name formation, as he incorrectly named other species for localities using the genitive case (-i or -ae). Regardless, the person after whom these localities were named is Lord Lamington, Charles Wallace Alexander Napier Cochrane-Baillie (1860–1940), was the 2nd Baron Lamington and a British colonial administrator, who served as the 8th Governor of Queensland (1896–1901) and the 14th Governor of Bombay (1903–1907). The description was published in English.
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| Toxicocalamus loriae Group species in live and perimortem photographs to show colour in life. A, B Toxicocalamus vertebralis sp. nov. (CAS 140042) from Kol, Jimi Valley, Jiwaka Province, PNG. C, D T. spilorhynchus sp. nov. (MCZ R-152431) from Garaina, Morobe Province, PNG. E T. atratus sp. nov. (MCZ R-84026) from Kundiawa, Wahgi Valley, Chimbu Province, PNG. F T. atratus (MCZ R-111767) from Kundiawa, Wahgi Valley, Chimbu Province, PNG. Photographs by Fred Parker. |
Toxicocalamus vertebralis sp. nov.
Etymology: The species epithet is a Latin masculine adjective in recognition of the vertebral stripe that distinguishes this species from most other Toxicocalamus.
Diagnosis: A large member of the T. loriae Group (known male SVL up to 565 mm, known female SVL up to 685 mm) with the following unique combination of characters: body length sexually dimorphic (t10 = 2.3826, p = 0.0192); two scales covering vent; three infralabials contacting first genial; a single intergenial between posterior genials, widest posteriorly; preocular contacting nasal (81%) or not (19%), not contacting internasal; relatively long snout (SNL/SNW mean = 1.07, range = 0.95–1.18); relatively large eye (EY/SNL mean = 0.21, range = 0.16–0.28); two postoculars; usually three (74%) posterior temporals; ventral scale count sexually dimorphic with overlap (t17 = 4.7511, p < 0.0001), 194–210 in nine males, 203–232 in nine females and a female embryo; subcaudals 39–52 in males, 31–38 in females, sexually dimorphic without overlap; SCR sexually dimorphic without overlap, 16.7–20.5% in males, 12.8–14.8% in females; adult females with much shorter tails than adult males, TLR 13.3–17.1% in adult males, 6.5–10.7% in adult females; pale parietal blotch absent; pale markings on prefrontals absent (95%) or vague (5%); tail spine white, paler than remainder of tail; and venter uniformly yellow.
Toxicocalamus spilorhynchus sp. nov.
Etymology: The species epithet is a Latinized masculine adjective formed by combining the Greek σπίλος (spilos, meaning spot) and ῥῠ́γχος (rhynchos, meaning snout), in recognition of the distinctive prefrontal blotch that typifies the species.
Diagnosis: A moderately sized member of the T. loriae Group (SVL up to 600 mm) with the following unique combination of characters: two scales covering vent; three infralabials contacting first genial; a single intergenial between posterior genials, widest posteriorly; preocular contacting nasal (87%) or not (13%), not contacting internasal (93.3%); relatively long snout (SNL/SNW mean = 1.16, range = 0.99–1.40); relatively large eye (EY/SNL mean = 0.22, range = 0.17–0.24); two postoculars (93%); usually three (67%) posterior temporals; ventral scale count sexually dimorphic with overlap (t12 = 3.7381, p = 0.001416), 172–184 ventrals in eight males, 178–197 in six females; subcaudals sexually dimorphic without overlap, 43–57 in males, 20–29 in females; SCR strongly sexually dimorphic, with the relative contribution of subcaudal scale number in males twice what it is in females (20.0–24.0 in males, 10.0–13.1 in females); pale parietal blotch usually absent (present in four small specimens); pale markings on prefrontals present; and venter uniformly yellow.
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| Uncollected juvenile Toxicocalamus atratus sp. nov. from Kutubu area, 1760 m elevation, Southern Highlands Province, PNG, to show the colouration in life. Photographs by Nick Baker. |
Toxicocalamus atratus sp. nov.
Etymology: The species epithet is a masculine Latin adjective meaning “dressed in black,” in recognition of the dark dorsal and ventral colouration of adults of this species.
Diagnosis: A large member of the T. loriae Group (male SVL up to 655 mm, female SVL up to 682 mm) with the following unique combination of characters: sexual size dimorphism in SVL present (t71 = 2.5689, p = 0.0062); two scales covering vent; posterior genials usually entirely separated (80%) but may be in anterior contact (20%) with each other; intergenial usually widest posteriorly (89%) or centrally (11%); preocular usually contacting nasal (77%), not contacting internasal; preocular rather short, less than twice as long as deep; postoculars two (one in 26%); posterior temporals two (58%) or three (42%); ventrals sexually dimorphic (t85 = 7.400, p < 0.00001), 177–206 in males, 187–218 in females; subcaudals sexually dimorphic with overlap (t87 = –24.8814, p < 0.00001), 40–47 in males, 26–41 in females; two scales covering vent; yellow nuchal collar and yellow markings on prefrontals present in juveniles, usually absent (but sometimes merely faded) in adults; tail spine paler than remainder of tail; and venter uniformly dark brown or dark brown with the posterior of each ventral paler brown or yellowish brown in adults, giving a banded appearance, black in life; venter yellow with a black spot on lateral margins of each ventral in juveniles.
Fred Kraus, Hinrich Kaiser and Mark O’Shea. 2022. Hidden Diversity in Semi-fossorial Melanesian Forest Snakes: A Revision of the Toxicocalamus loriae Complex (Squamata, Elapidae) from New Guinea. Vertebrate Zoology. 72: 997-1034. DOI: 10.3897/vz.72.e89647