Gerrhopilus addisoni KRAUS, 2017
Can you confirm these amateur observations of Gerrhopilus addisoni?
|Higher Taxa||Gerrhopilidae, Typhlopoidea, Serpentes, Squamata (snakes)|
|Synonym||Gerrhopilus addisoni KRAUS 2017|
Typhlops depressiceps — WALLACH 1996: 110
|Distribution||Papua New Guinea (Milne Bay Province)|
Type locality: Panaete Island, Deboyne Group (10.68° S, 152.35° E; 0–50 m a.s.l.), Milne Bay Province, Papua New Guinea.
|Types||Holotype: USNM 195953, Adult female, collected on 24 March 1969 by H. Heatwole.|
|Diagnosis||Diagnosis. This species belongs to Gerrhopilus based on the presence of head glands in the centers of the anterior head shields in addition to their anterior margins (McDowell 1974; Wallach 1996b). A relatively robust (adult L/M = 58) species of Gerrhopilus having the unique combination of a rostrate snout with a transverse keel on the ventral margin of the rostral that extends ventral to the rictus, angle of pre-oral snout in lateral aspect horizontal to the body axis, a vestigial eye lacking a distinct pupil, preocular covering two-thirds of the eye in lateral view, longitudinal scale rows 24/22/20, transverse scale rows posterior to the rostral 627, supralabial imbrication pattern T-V, subocular scale one, presubocular scale absent, prefrontals and supraoculars larger than frontal and parietals and interparietal, subcaudal scales 26, L/W ratio 80, and tail spine oriented ventrally at an angle of 90 ̊ to axis of anteroventral surface of that terminal scale (and, hence, to body axis). Refer to Table 1 for additional diagnostic qualitative and quantitative features.|
Comparisons. Gerrhopilus addisoni may be distinguished from all other members of Gerrhopilus except G. depressiceps and G. mcdowelli in having a transverse keel on the ventral margin of the rostral, which gives the snout a beaked appearance in lateral aspect, and in having a posterior reduction of four longitudinal scale rows from head to vent. Gerrhopilus addisoni may be distinguished from G. depressiceps by its vestigial eye lacking a distinct pupil (eye well-defined and with a pupil in G. depressiceps); anterior two-thirds of eye covered by preocular in lateral view (vs. preocular barely touching anterior margin of eye in G. depressiceps); convex posterior margin of the rostral (vs. concave in G. depressiceps); narrower body (L/W = 80 in G. addisoni vs. 57–67 in G. depressiceps); prefrontal and supraoculars larger than frontal, parietals, and interparietal; and tail spine pointed ventrally at 90° to axis of anteroventral surface of that terminal scale (vs. posteroventrally at 70° in G. depressiceps). Gerrhopilus addisoni may be distinguished from G. mcdowelli by its greater length (304 mm vs. 94– 199 mm in G. mcdowelli), greater number of mid-dorsal scale rows (627 vs. 431–464 in G. mcdowelli), narrower body (L/W = 80 in G. addisoni vs. 44–53 in G. mcdowelli), pre-oral snout oriented horizontally (vs. inclined at 30° from horizontal in G. mcdowelli), and rostral keel pointing directly downward (vs. anteroventrally in G. mcdowelli).
|Comment||Habitat: the holotype was collected under the bark of a tree 4.5 m above ground.|
|Etymology||The specific epithet is a genitive honorific for Addison Wynn of the United States National Museum in recognition of his work on scolecophidian snakes.|