Toxicocalamus vertebralis, Kraus & Kaiser & O’Shea, 2022

Kraus, Fred, Kaiser, Hinrich & O'Shea, Mark, 2022, Hidden diversity in semi-fossorial Melanesian forest snakes: A revision of the Toxicocalamus loriae complex (Squamata, Elapidae) from New Guinea, Vertebrate Zoology 72, pp. 997-1034 : 997

publication ID

https://dx.doi.org/10.3897/vz.72.e89647

publication LSID

lsid:zoobank.org:pub:0CA196A2-00E0-4E0A-B216-11AD5B3856EB

persistent identifier

https://treatment.plazi.org/id/B622F878-E540-4FF4-9D8E-1E1C91325F07

taxon LSID

lsid:zoobank.org:act:B622F878-E540-4FF4-9D8E-1E1C91325F07

treatment provided by

Vertebrate Zoology by Pensoft

scientific name

Toxicocalamus vertebralis
status

sp. nov.

Toxicocalamus vertebralis sp. nov.

Figs 4I, J View Figure 4 , 8 View Figure 8 , 9 View Figure 9 , 10 View Figure 10 , 11A, B View Figure 11

Toxicocalamus (Apistocalamus) loriae (part) - McDowell, 1969: 485.

Holotype.

AMS R23072, an adult female collected by Harold G. Cogger at Fungoi, Kaironk Valley, 5.33°S, 144.42°E, elevation 1800 m, Schrader Range, Madang Province, Papua New Guinea in December 1964.

Paratypes (n = 18).

Papua New Guinea: Madang Province: same locality as holotype, AMS R23068-69, R23071, R23073; Kaironk Valley, 5.23°S, 144.48°E, elev. 1850 m, UPNG 963-67, 3353, 5012; Kalne River, 5.53°S, 144.82°E, elev. 1200 m, UPNG 8695; Morobe Province: Wau, 7.33°S, 146.71°E, elev. 1070 m, KU 129086; ridge between Aseki and No. 1 Watut Valley, ca. 30 km W Wau, 7.33°S, 146.17°E, elev. ca. 2000 m, BPBM 6497; Western Highlands Province: Kol, Jimi Valley, 5.70°S, 144.84°E, elev. 1500 m, CAS 140042; Baiyer River, 5.53°S, 144.16°E, elev. 1170 m, AMS R16575, R16581; Sandaun Province: Busilmin, 4.92°S, 141.14°E, elev. 1880 m, SAMA 6275.

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 (t 10 = 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 (t 17 = 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.

Comparisons with other species.

Toxicocalamus vertebralis can be distinguished from all other members of the T. loriae Group except T. loennbergii by its dark vertebral line. It is further distinguished from T. mattisoni and T. nigrescens by its greater number of ventrals (198-228 vs. 170-181 and 184-193 in T. mattisoni and T. nigrescens , respectively) and yellow venter (grey or yellow barred with grey in T. mattisoni and T. nigrescens ); from T. loriae in having only a single intergenial (vs. two in T. loriae ); from juvenile T. nymani by lacking a pale blotch on the prefrontals (vs. present in 80% of T. nymani ) and from all T. nymani by significant differences in ventral scale counts for both sexes (males: 194-210 vs. 178-198 in T. nymani , t 24 = 5.2049, p = 0.000012; females: 203-232 vs. 182-210 in T. nymani , t 30 = 7.3288, p <0.00001) and subcaudal scale counts in females (31-38 vs. 26-39 in T. nymani , t 29 = -3.5633, p = 0.000645); and from T. lamingtoni in having two scales covering the vent (vs. one scale in T. lamingtoni ), non-overlapping ventral scale counts in both sexes (males: 194-210 vs. 160-178 in T. lamingtoni ; females: 203-232 vs. 189-194 in T. lamingtoni ) and subcaudal scale counts in females (31-38 vs. 26-34 in T. lamingtoni ; t 17 = -4.9232, p = 0.000064), and a white (vs. dark brown in T. lamingtoni ) tail spine. The uniformly yellow venter and dark vertebral stripe make T. vertebralis most similar to T. loennbergii , but it can be distinguished from that species in having two postoculars (vs. one in T. loennbergii ), a significantly greater number of subcaudals in females (31-38 vs. 23-32 in T. loennbergii ; t 12 = -4.3818, p = 0.000447), three (vs. four) infralabials contacting the anterior pair of genials, a longer snout (SNL/SNW mean = 1.07, range = 0.95-1.18 vs. 0.95 and 0.93-0.99 in T. loennbergii ), larger eye (EY/SNL mean = 0.21, range = 0.16-0.28 vs. 0.16 and 0.15-0.18 in T. loennbergii ), and lacking a pale blotch on the parietals (present in T. loennbergii ).

Description of the holotype.

Adult female with mid-ventral slit extending through 47 ventrals anterior to vent; 666 mm SVL + 69 mm TL = 735 TTL. Rostral broader than high, notched ventromedially, extending dorsoposteriorly behind nares; internasals angulate, semi-triangular, wider than long (Fig. 8A, A View Figure 8 '); prefrontals distinct from preoculars, approximately square, wider anteriorly than posteriorly, rounded posterolaterally, bordered below by preocular and nasal; preoculars elongate, narrower anteriorly, approximately twice as long as deep, bordered anteriorly by nasal, bordered below by second and fourth supralabials on right (Fig. 8B, B View Figure 8 ') and by second and third supralabials on left (Fig. 8C, C View Figure 8 '); frontal shield-shaped, lateral margins angled obliquely, not fused with supraoculars, anterior margin extending slightly anterior to remainder of scale medially; parietals approximately twice as long as wide. Nasals divided by large nares, without grooves above or below naris. Postoculars two, upper longer and larger than lower, both smaller than eye; one elongate anterior temporal above fifth and sixth supralabials on left, sixth and seventh supralabials on right, separating supralabials from parietal; two posterior temporals on left, three on right, lowest abutting posterodorsal margin of sixth supralabial. Supralabials six on left, seven on right; third and fourth supralabials contacting eye on left, fourth and fifth supralabials contacting eye on right; infralabials six, first three in contact with anterior genial, third and fourth in contact with posterior genials. Mental small, shallow, triangular, wider than deep, bordered behind by first supralabials; anterior genials slightly larger than posterior genials, in medial contact along entire length; posterior genials in point contact anteriorly; intergenial single, widest posteriorly; five gulars separate intergenial from first ventral in the midline; first sublabial separates posterior genial from fifth infralabial (Fig. 8D, D View Figure 8 '). Eye relatively small; pupil round.

Dorsal scale rows 15-15-15, smooth, not notched posteriorly, without apical pits. Ventrals 220, each approximately four times wider than long; two scales covering vent; subcaudals 33, paired. Tail tipped by a pointed conical spine.

In preservative (52 years after collection), dorsum pale brown (Fig. 9A View Figure 9 ), with darker brown vertebral stripe one scale wide; lowest one and one-half dorsal scale rows yellow, with brown spots on ventral margin of each scale on approximately posterior three-fourths of body, giving this ventrolateral region the appearance of being striped. Venter and subcaudals uniformly pale yellow (Fig. 9B View Figure 9 ). Supralabials pale yellow ventrally, brown dorsally on supralabials 3-6 on left, 4-7 on right. Remnants of a yellow nuchal collar present but widely infused with brown, not meeting mid-dorsally. Nasals largely yellow; yellow mottling on rostral, internasals, dorsal portions of nasals, and anterior portions of preoculars. Chin and throat pale yellow, with few small brown flecks along sutures joining mental, first two infralabials, and anterior genials. Conical tail spine white with brown tip. Iris black.

Variation.

Ventrals 194-210 (201 ± 5) in nine males and 203-232 (218 ± 9) in ten females; subcaudals 39-52 (45 ± 4) in nine males and 31-38 (35 ± 2) in ten females; SCR 16.7-20.5% (18.4 ± 1.0%) in males, 12.8-14.8% (13.7 ± 0.7%) in females. The lowest male ventral and subcaudal counts are in SAMA 6275 from Busilmin (194 and 39, respectively) but these are not strong outliers. Numbers of postoculars are two, except on the left side of AMS R16581, which has one. TLR 13.3-17.1% (14.7 ± 1.3%) in six adult males, 6.5-10.7% (9.4 ± 1.4%) in six adult females, sexually dimorphic without overlap. Numbers of posterior temporals are usually three (74%) but sometimes two (24%) or four (3%). Preoculars typically broadly contact the nasals, except for two specimens that have the two scales separated by point contact between the prefrontal and second supralabial; a third specimen (UPNG 8695) has the two scales separated by broad contact between the prefrontal and second supralabial. Typically, only a single intergenial separates the posterior genials; however, two specimens also have a small intercalary scale anterior to the intergenial and between the posterior genials, and a third specimen has three small intergenials: one anterior and two posterior. Posterior genials are entirely separated by the intergenial(s) in ten specimens and in anterior contact for ¼-½ their length in eight.

Specimens are red brown (Fig. 10A View Figure 10 ) or medium brown (Fig. 10B View Figure 10 ) dorsally with a dark-brown vertebral stripe. Venters are uniformly yellow at all sizes. Heads are dark above in all specimens except in the one from Busilmin (SAMA 6275), which is vaguely mottled with dark yellow on several scales. All supralabials are yellow, except for the upper portions of the larger scales; the nasal and ventral portion of the rostral are also typically coloured with yellow. Chin and throat typically uniformly yellow, but a few brown flecks may occur anteriorly, and the specimen from Busilmin has the junctions between the infralabials narrowly margined in brown. In neonates and small juveniles (153-213 mm) the nuchal collar consists of a lateral yellow crescent on each side of the neck, each of which narrows medially and almost meets its opposite member (Fig. 4I, J View Figure 4 ). In larger animals, these yellow blotches are invaded with brown and become obscure.

Colour in life.

A photo of CAS 140042, a large (685 mm SVL) male, shows a dark-brown animal with a darker-brown vertebral region and yellow venter, lips, and tail spine (Fig. 11A, B View Figure 11 ).

Range.

Known from the Schrader and Bismarck Ranges at the eastern end of the Central Highlands of Papua New Guinea, the vicinity of Wau (Morobe Province), and the Star Mountains near the Indonesian border, at elevations from 1170-1880 m (Fig. 6B View Figure 6 ).

Kingdom

Animalia

Phylum

Chordata

Class

Reptilia

Order

Squamata

Family

Elapidae

Genus

Toxicocalamus

Loc

Toxicocalamus vertebralis

Kraus, Fred, Kaiser, Hinrich & O'Shea, Mark 2022
2022
Loc

Toxicocalamus (Apistocalamus) loriae

Kraus & Kaiser & O’Shea 2022
2022