Gerrhopilus hades (KRAUS, 2005)
Can you confirm these amateur observations of Gerrhopilus hades?
|Higher Taxa||Gerrhopilidae, Typhlopoidea, Serpentes, Squamata (snakes)|
|Synonym||Typhlops hades KRAUS 2005|
Gerrhopilus hades — VIDAL et al. 2010
Gerrhopilus hades — WALLACH et al. 2014: 308
|Distribution||Papua New Guinea (Milne Bay Province: NE end of Rossel Island in the Louisiade Archipelago).|
Type locality: forest along Rupu River at Bibikea, 11.33537°S, 154.22470°E, 280 m elevation, Rossel Island, Milne Bay Province, Papua New Guinea
|Types||Holotype: BPBM 20819 (field tag FK 10449), adult male, collected by F. Kraus on 14 May 2004.|
|Diagnosis||Diagnosis.—A small, thin species of Typhlops having a rounded snout, distinct pupil in the eye, 18 scale rows throughout, 343 middorsal scales between the rostral and tail spine, T-V supralabial- imbrication pattern (for definitions of these patterns, see Wallach, 1993), one subocular scale, head glands evenly but sparsely dispersed among the anterior head scales but absent from the centers of the ocular and subocular scales, and anterior two-thirds of the eye covered by the preocular plate.|
Typhlops hades belongs to the T. ater species group (McDowell, 1974) based on the presence of head glands in the centers of the head shields in addition to their anterior margins (Wallach, 1996). Among members of this species group, T. hades may be distinguished from Typhlops depressiceps, Typhlops fredparkeri, T. inornatus, T. mcdowelli, and Typhlops oligolepis in having 18 (vs. 16 in Typhlops fredparkeri and T. oligolepis and 20+ in the remaining species) midbody scale rows; from Typhlops beddomii, T. hedraeus, and Typhlops tindalli in having a subocular scale and supralabial- imbrication pattern T-V (vs. T-II in the three Asian species); and from the geographically remote Typhlops andamanensis, T. ater, Typhlops bisubocularis, and Typhlops floweri in lacking a presubocular. It further differs from the first three of those species in having supralabial- imbrication pattern T-V (vs. T-II).
Typhlops hades is the only typhlopid from Papua New Guinea to have the combination of head glands in the centers of the head shields and 18 midbody scale rows. In Wallach’s (1996) key to typhlopids from Papua New Guinea, T. hades would key out to T. inornatus. In addition to number of midbody scale rows, the new species differs from T. inornatus in being of smaller size, narrower habitus (TL/mass 5 102–184 mm/g in T. hades and 46–69 mm/g in T. inornatus; Table 1), having approximately two-thirds of the eye lying under the preocular plate (vs. 50% or less in T. inornatus), and having no head glands in the centers of the ocular and subocular shields (generally but not invariably present in T. inornatus). The new species also has far fewer glands present in the centers of the rostral, preocular, and superior nasal scales. This is most easily compared under the preocular scales because of their reduced gland numbers. For this scale, T. hades has 10–11 centrally arrayed glands (Fig. 1) vs. 39 in the preocular of a typical T. inornatus [from KRAUS 2005].
|Comment||Typhlops hades is a member of the Typhlops ater species group and is|
characterized by having 18 scale rows, 343 middorsal scales, T-V supralabial-imbrication pattern, a distinct pupil, single subocular scale, and by lacking a presubocular scale. Its closest living relative is probably Typhlops inornatus, known from forested habitats on the nearby mainland of New Guinea. T. hades is known from only two specimens from northeastern Rossel Island, and it remains uncertain whether it occurs on adjacent islands of the Louisiade Archipelago.
|Etymology||Named after the Greek god of the underworld, Hades.|