Toxicocalamus mattisoni KRAUS, 2020
Can you confirm these amateur observations of Toxicocalamus mattisoni?
|Higher Taxa||Elapidae (Hydrophiinae), Colubroidea, Caenophidia, Alethinophidia, Serpentes, Squamata (snakes)|
|Synonym||Toxicocalamus mattisoni KRAUS 2020|
|Distribution||Papua New Guinea (Milne Bay Province: north slope of Mt. Simpson, 1300–1490 m elevation)|
Type locality: Siyomu Village, 10.0145° S, 149.5970° E, 1300 m a.s.l., N slope of Mt. Simpson, Milne Bay Province, Papua New Guinea
|Types||Holotype. BPBM 17988 (field tag FK 7524), obtained from local villagers on 23 February 2003.|
Paratypes (n = 6). Papua New Guinea: Milne Bay Province: N. slope of Mt. Simpson: Siyomu (BPBM 17987, 18165, PNGNM R-25152); Bunisi Village, 10.0171° S, 149.6002° E, 1420 m a.s.l. (BPBM 17989, 18166); Camp 2, 0.5 km SW Bunisi, 10.0209° S, 149.5947° E, 1490 m a.s.l. (BPBM 18164).
|Diagnosis||Diagnosis: A moderately sized species of Toxicocalamus (maximum SVL = 483 mm) having 15-15-15 scale rows, 170–181 ventrals, 33–49 paired subcaudals, divided anal plate, preocular distinct from prefrontal, separated from nasal by prefrontal contact with second supralabial; frontal unfused with supraoculars; internasals unfused; one postocular; one anterior temporal, 2–3 posterior temporals; six supralabials, second in contact with prefrontal, excluding contact between preocular and nasal; uniformly gray or brown dorsum; and venter pale gray or yellow with gray bands across each ventral scale.|
The new species differs from T. holopelturus McDowell in having divided (vs. entire) subcaudals; from T. buergersi (Sternfeld), T. cratermontanus Kraus, T. longissimus Boulenger, T. mintoni Kraus, T. misimae McDowell, T. preussi (Sternfeld), and T. stanleyanus Boulenger in having the preocular distinct from (vs. fused to) the prefrontal; from T. pumehanae O’Shea, Allison & Kaiser in having the prefrontal distinct from (vs. fused to) the internasal; from T. pachysomus Kraus by its slender habitus (vs. robust in T. pachysomus) and in having the internasal and preocular not in contact (vs. internasal and preocular in contact in T. pachysomus); and from T. ernstmayri, T. grandis, and T. spilolepidotus McDowell in its unspotted, uniformly gray or brown dorsal color (vs. yellow brown spotted with dark brown in T. ernstmayri, dark brown with whitish blotches in T. grandis, black with each scale containing a pale-yellow spot in T. spilolepidotus).
Toxicocalamus mattisoni is most similar in scalation to T. loriae, T. nigrescens, and nomina currently synonymized with T. loriae (Apistocalamus pratti, A. loennbergii, A. lamingtoni, and Pseudapistocalamus nymani). It differs from A. lamingtoni in having a divided (vs. single) anal plate and from all the remainder except A. loennbergii in having the preocular not contacting the nasal due to contact between the prefrontal and second supralabial (vs. preocular contacting nasal in T. loriae and T. nigrescens). In A. loennbergii, the preocular and nasal scales may or may not be in contact, being narrowly separated in BMNH 1918.104.22.168 on the right side and in point contact on the left; they are in contact in BMNH 1922.214.171.124–26. Toxicocalamus mattisoni differs from A. loennbergii in having fewer ventrals (170–181 vs. 213–220 in A. loennbergii) and a gray or yellow venter with each ventral barred in darker gray (vs. uniform bright yellow in A. loennbergii). Toxicocalamus mattisoni further differs from T. loriae (and A. pratti) in having a gray or yellow venter with each ventral barred in darker gray (vs. yellow, usually with a mid-ventral row of brown spots in T. loriae) and from T. nigrescens in its smaller size (SVL up to 483 in T. mattisoni vs. up to 635 in T. nigrescens) and paler dorsal color (medium gray or brown in T. mattisoni vs. dark charcoal gray or gray brown in T. nigrescens).
Color in life. From notes in life, I described the holotype as “Dorsum olive brown. Head black. Lips lemon yellow, remainder of belly light yellow, with gray suffusion anteriorly. Under tail charcoal gray.” Small amounts of yellow can be seen on the prefrontals of the holotype in a photo of that animal (Fig. 2). Adult paratype BPBM 17989 had a gray dorsum changing to olive brown on lower sides; venter dusky yellow-orange with each ventral having a gray anterior margin; black under the tail; lips and nuchal collar dusky yellow-orange. The juvenile paratype (BPBM 17987) was: “Dorsum gray, darker on head. Lips lemon yellow, chin yellow with gray cast, remainder of venter gray with purplish cast.”
|Etymology||Named after Dr. Erik Mattison, a friend of the author who has generously supported his research in New Guinea.|