Cyrtodactylus arcanus OLIVER, RICHARDS & SISTROM, 2012
Can you confirm these amateur observations of Cyrtodactylus arcanus?
|Higher Taxa||Gekkonidae, Gekkota, Sauria, Squamata (lizards: geckos)|
|Synonym||Cyrtodactylus arcanus OLIVER, RICHARDS & SISTROM 2012|
Cyrtodactylus aenigma OLIVER, RICHARDS & SISTROM 2012 (nom. nud.)
|Distribution||Papua New Guinea (Madang)|
Type locality: Papua New Guinea, Madang Province, ca. 23 km SE Bundi (05°47’ S, 145°16’ E), brought in by local collectors from around a village referred to as ‘Dagbaru’, exact locality unknown.
|Types||Holotype: AMS R124559, f, 29 April 1987, preserved and photographed by T. Reardon. Tissue frozen and stored at the South Australian Museum.|
Paratype. AMS R124560, adult female with same collec- tion information as holotype.
|Diagnosis||Diagnosis and comparisons. Distinguished from all other Melanesian and Wallacean Cyrtodactylus by the following unique combination of character states: moderate size (SVL up to at least 92 mm); relatively narrow head (HW ⁄ SVL 0.18); enlarged precloacal and femoral scales in an unbroken row extending full length of femur; medial row of transversely enlarged subcaudal scales approximately one- quarter to a third width of tail; caudal tubercles extending <20 mm from base of tail and on dorsal surface only; dorsal cephalic tubercles sparse in the mid-dorsal region posterior to orbitals; and dorsal coloration consisting of 7–9 relatively thin transverse dark-brown bands or series of blotches lacking distinct lighter edges on a medium-brown background.|
The combination of medium size (up to 92 mm), widened subcaudals and enlarged precloacal and femoral scales serves to distinguish Cyrtodactylus arcanus from most other Melanesian Cyrtodactylus. Of those species that share these characters, Cyrtodactylus aaroni and C. mimikanus can be distinguished by the presence of a distinctive dorsal pattern consisting of six or seven wide chocolate brown bands separated by very thin, strongly defined light bands (Günther & Rösler 2003), and C. boreoclivus can be distinguished by its larger size (SVL 104–109 mm), wider head (HW ⁄ SVL 0.19–0.20 vs. 0.18) and lower number of wider and much more indistinctly edged transverse dorsal bands. Cyrtodactylus capreoloides is superficially similar in appear- ance but can be readily distinguished by its much narrower subcaudals; it also tends to have more extensive cephalic tuberculation (dense close to the posterior edge of the orbitals) and a lower number of mid-body scale rows (20– 22 vs. 22–25).
As the type series includes only females, the precloacal and femoral pore arrangement of this species is unknown, but when determined will likely aid diagnosis from a suite of additional Melanesian Cyrtodactylus species.
|Comment||Abundance: only known from its original description (Meiri et al. 2017).|
|Etymology||Latin ‘arcanus’, secret or mysterious, in reference to the paucity of information about this species, specifically the imprecise type locality, and absence of both habitat data and male specimens. The name “aenigma” was meant to be a manuscript name only that slipped through the editing process and remained for C. arcanus in Table 2 (Paul Oliver, pers. comm., 30 Sep 2012).|