Gerrhopilus flavinotatus, Kraus, 2023

Kraus, Fred, 2023, A revision of Gerrhopilus inornatus (Squamata: Gerrhopilidae) reveals a multi-species complex, Zootaxa 5231 (1), pp. 1-23 : 14-15

Gerrhopilus flavinotatus sp. nov.

Figs. 5C, D

Typhlops inornatus Wallach 1996: 113 .

Gerrhopilus inornatus Pyron & Wallach 2014: 79 .

Holotype. MCZ 175100 (field tag Y-31495), collected on 29 March 1969 by Fred Parker at Menemsore, 5.88 S, 141.23 E, 1830 m a.s.l., Western Province, Papua New Guinea.

Diagnosis. A Gerrhopilus species characterized by the unique combination of having a rounded snout in lateral view; LSR = 22 at midbody; TSR = 327; loreal absent; supralabial imbrication pattern T-V; subocular scale one; presubocular scale absent; a sharp, protruding spine on the tail tip that is white; 3 glands in the prefrontal, 6–8 in the supraocular, 0 in the ocular and frontal, 24–28 in the preocular, and 0–4 in the subocular; L/W = 26.6; TL/SVL = 0.037; and a dark-brown venter with 2–4 rows of yellow scales mid-ventrally on the posterior half of the body with brown scales scattered in this yellow field. Its size is small for this species group ( Table 1 ).

Comparisons with other species. Gerrhopilus flavinotatus is distinguished from G. fredparkeri , G. hades , G. inornatus , G. slapcinskyi , and G. suturalis in having 22 longitudinal scale rows at midbody (vs 16 in G. fredparkeri , 18 in G. hades and G. suturalis , and 20 in G. inornatus and G. slapcinskyi ). It is further distinguished from G. fredparkeri in having fewer transverse scale rows (327 vs 539 in G. fredparkeri ), as it is from G. papuanorum and G. wallachi (407–414 rows in G. papuanorum and 430 rows in G. wallachi ) and apparently from G. inornatus (374–375 rows in G. inornatus ). It is further distinguished from G. inornatus in being more robust (L/W = 26.6 vs 36.4–47.8 in G. inornatus ); from G. slapcinskyi in lacking glands in the ocular (vs 4–9 in G. slapcinskyi ), having more glands in the supraocular (6–8 vs 0–3 in G. slapcinskyi ), fewer glands in the preocular (24–28 vs 35–39 in G. slapcinskyi ), and a white tail spine (vs black in G. slapcinskyi ); from G. papuanorum in being more robust (L/W = 26.6 vs 51.2–53.5 in G. papuanorum ) and having a longer tail (TL/SVL = 0.037 vs 0.021 –0.026 in G. papuanorum ); from G. hades in having 22 longitudinal scale rows behind the head (vs 18 in G. hades ); from G. suturalis in having a single postocular on each side of the head (vs two in G. suturalis ) and lacking a presubocular (vs present in G. suturalis ); and from G. wallachi in having a sharp, protruding tail spine (vs short, blunt, and downturned in G. wallachi ), lacking glands in the ocular (vs 9–11 in G. wallachi ), and having fewer glands in the prefrontal (3 vs 9 in G. wallachi ) and preocular (24–28 vs 33–35 in G. wallachi ). Gerrhopilus flavinotatus is distinguished from G. polyadenus in lacking glands in the ocular (vs 11–23 in G. polyadenus ) and having fewer glands in the subocular (0–4 vs 5–16 in G. polyadenus ) and preocular (24–28 vs 42–50 in G. polyadenus ). Gerrhopilus flavinotatus is further distinguished from all other Melanesian Gerrhopilus except G. wallachi in having a venter that is brown with yellow mid-ventral scales throughout the posterior third of the body (vs venter uniformly brown in all the other species).

Description of the holotype. Immature female. L = 154.5 mm, SVL = 149 mm, TL = 5.5 mm, HW = 4.1 mm, SN = 1.6 mm, SW = 3.3 mm, PSN = 1.1 mm, RW = 1.6 mm, EW = 0.3 mm, W = 5.8 mm, VW = 4.3 mm, TW = 3.5 mm, L/W = 26.6, TL/SVL = 0.037. Head slightly wider than neck. Snout rounded in dorsal and lateral views. Snout anterior to lower jaw horizontal, parallel to body axis. Rostral rather narrow (RW/HW = 0.39), oval dorsally, lateral margins convex, posterior border extending approximately two-thirds way between naris and eye, posterior margin convex; ventrally surface papillose, with sides and posterior margin straight. Nasals separated dorsally by prefrontal ( Fig. 5C ); superior nasal large, with slightly sinuous posterior margin, concave dorsally, convex ventrally ( Fig. 5D ). External naris semicircular, close to rostral, anterior half covered by inferior nasal; superior nasal suture extending anterodorsally from naris to rostral; inferior nasal suture complete, contacting second supralabial posterior to latter’s contact with first supralabial. Prefrontal subequal to supraoculars. Supraoculars wider than long, longest at medial third, tapering toward eye, larger than parietals and interparietal, which are subequal in size. Frontal divided into two scales, left overlapping right, subequal in size to parietals. Preocular large, triangular; somewhat larger than ocular but smaller than superior nasal. Ocular large, smaller than preocular, extending dorsally well above preocular and to center of suproculars, extending ventrally to ~2/3 depth of preocular, bordered posteroventrally by subocular of approximately half its size. Eye fairly obscure, with pale pupil, situated at widest point of ocular and approximately midway along its height, anterior half covered by preocular plate in lateral view. Four postoculars bordering ocular and subocular between parietal and fourth supralabial. Four supralabials, third the largest, all except first with long axis oblique to long axis of body, first approximately square. Supralabial imbrication pattern T-V, posterior border of second supralabial overlaps anteroventral margin of preocular, that of third supralabial overlaps anteroventral margin of subocular and extends posterior to rear margin of preocular. Mental hexagonal, wider than long, projecting slightly beyond curve of lower jaw and fitting into notch on upper lip when mouth is closed. Infralabials two on each side, second much longer.

Longitudinal scale rows uniformly 22 behind head, at midbody, and anterior to vent; transverse scale rows 327, six intercalary scales along vertebral row; subcaudals 12; dorsocaudals 12; apical region with sharp, laterally compressed, corneous spine that extends well past last scales.

Rostral, nasals, and preoculars densely covered in pale glands; oculars with 0 glands, preoculars with 24 (R) and 28 (L), supraoculars with 6 (R) and 5 (L), prefrontal with 3; frontal with 0, and suboculars with 0 (R) and 4 (L).

In preservative, 53 years after preservation, dorsum and sides uniformly brown, each scale darker anteriorly. Venter brown, with a few pale straw-yellow scales scattered mid-ventrally posterior to midbody, with posterior third of venter comprised of 2–4 mid-ventral rows of pale straw-yellow scales with brown scales scattered among them, the yellow scales becoming more continuous and predominant toward the tail. Subcaudals and tail spine pale straw yellow. Chin, mid-ventral throat, infralabials, first three supralabials, and anterior half of rostral pale straw yellow. Iris black; pupil pale gray.

Etymology. The specific epithet is a masculine compound adjective from the Latin flavus, meaning yellow, and notatus, meaning mark, in reference to the distinctive ventral color pattern.

Distribution. Known only from the type locality ( Fig. 2 ).

Remarks. The sole specimen was examined by Wallach (1996) and Pyron & Wallach (2014) who listed it as Typhlops inornatus .

Figures

FIGURE 2. Map of southern Papua New Guinea showing collecting localities for Gerrhopilus inornatus (star), G. flavinotatus (diamond), G. lorealis (hexagon), G. papuanorum (square), G. polyadenus (open circles), G. slapcinskyi (filled circle), and G. wallachi (triangle).

FIGURE 5. Dorsal and lateral views of heads for members of the Gerrhopilus inornatus Group having 22 midbody scale rows and venters marked with yellow. A, B holotype of Gerrhopilus wallachi (MCZ 140724); C, D holotype of Gerrhopilus flavinotatus (MCZ 175100); E, F holotype of Gerrhopilus lorealis (BPBM 2272).