Celestus oligolepis, Schools & Hedges, 2024

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 97-100

Celestus oligolepis sp. nov.

Jamaican Few-scaled Forest Lizard

(Fig. 32)

Celestus crusculus — Schwartz & Henderson, 1991:369 (part).

Celestus crusculus crusculus — Hedges et al., 2019:17 (part).

Celestus crusculus — Schools & Hedges, 2021:220 (part).

Celestus crusculus — Landestoy et al., 2022:204 (part).

Holotype. USNM 328158 , a juvenile from 7.0 km WSW of Old Hope , Westmoreland Parish, Jamaica, collected by S. Blair Hedges and Carla Ann Hass on 29 May 1988 (18.2232, -78.2861; 0 m).

Diagnosis. Celestus oligolepis sp. nov. has (1) a dorsal pattern of dots in chevrons, (2) head markings present, (3) markings in the longitudinal paramedian area present, (4) dots arranged in bars in the lateral band absent, (5) a SVL of 30.7 mm (juvenile, only specimen), (6) ventral scale rows, 98, (7) midbody scale rows, 35, (8) total lamellae on one hand, 30, (9) total strigae on ten scales, 83, (10) relative length of all digits on one hindlimb, 34.6 %, (11) relative distance between the angled subocular and mouth, 0.651 %, (12) relative eye length, 4.85 %, (13) relative forelimb length, 21.4 %, (14) relative ear width, 2.28 %, (15) relative rostral height, 2.11 %, (16) relative head length, 19.5 %, (17) relative mental width, 2.28 %, (18) relative postmental width, 4.20 %, (19) relative cloacal width, 8.95 %, (20) relative prefrontal width, 6.41 %, (21) relative largest supraocular width, 4.03 %, (22) relative longest finger length, 5.14 %, (23) relative distance between the ear and eye, 9.14 %, (24) relative head width, 78.3 %, (25) relative frontal width, 74.3 %, (26) relative nasal height, 2.34 %, (27) relative angled subocular height, 1.89 %, (28) relative distance between the eye and naris, 5.63 %, (29) relative canthal iii length, 2.77 %, (30) relative angled subocular width, 3.12 %, and (31) relative nasal length, 2.44 %. The species stem time is 4.20 Ma and the species crown time is unavailable (Fig. 4).

Because the only known specimen of Celestus oligolepis sp. nov. is a juvenile, we only differentiate it from other species of Celestus based on pattern and scale count characters. Although pattern can have ontogenetic differences, the number of scales usually does not change with age. Celestus oligolepis sp. nov. has a smaller number of midbody scale rows than most other species of the genus.

From Celestus barbouri , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus chevrons), the longitudinal paramedian lines (present versus absent), the ventral scale rows (98 versus 118–151), the midbody scale rows (35 versus 47–56), and the total lamellae on one hand (30 versus 36–49). From C. capitulatus sp. nov., we distinguish C. oligolepis sp. nov. by the midbody scale rows (35 versus 37–47). From C. crusculus , we distinguish C. oligolepis sp. nov. by the midbody scale rows (35 versus 37–44). From C. duquesneyi , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus bands), the head markings (present versus absent), the longitudinal paramedian lines (present versus absent), and the total lamellae on one hand (30 versus 64). From C. hesperius sp. nov., we distinguish C. oligolepis sp. nov. by the head markings (present versus absent), the ventral scale rows (98 versus 111–114), and the midbody scale rows (35 versus 39–44). From C. hewardi , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus mottled/bands), the head markings (present versus absent), the ventral scale rows (98 versus 113–137), the midbody scale rows (35 versus 43–59), and the total lamellae on one hand (30 versus 50–61). From C. jamesbondi sp. nov., we distinguish C. oligolepis sp. nov. by the relative mental to vent scales (2.80 versus 2.14–2.77) (see Remarks). From C. macrolepis , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus bicolored), the head markings (present versus absent), the longitudinal paramedian lines (present versus absent), the ventral scale rows (98 versus 112–116), the midbody scale rows (35 versus 46–48), and the total lamellae on one hand (30 versus 52–54). From C. macrotus , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus chevrons/bands), the dots arranged in bars in the lateral areas (absent versus present), the ventral scale rows (98 versus 87–93), the midbody scale rows (35 versus 41–45), and the total lamellae on one hand (30 versus 39–40). From C. microblepharis , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus chevrons), the head markings (present versus absent), and the longitudinal paramedian lines (present versus absent). From C. molesworthi , we distinguish C. oligolepis sp. nov. by the ventral scale rows (98 versus 102–125), the midbody scale rows (35 versus 41–49), and the total lamellae on one hand (30 versus 32–44). From C. occiduus , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus absent), the head markings (present versus absent), the longitudinal paramedian lines (present versus absent), the ventral scale rows (98 versus 109–134), the midbody scale rows (35 versus 46–56), the total lamellae on one hand (30 versus 50–66). From C. striatus , we distinguish C. oligolepis sp. nov. by the dorsal pattern (dots in chevrons versus absent/chevrons), the ventral scale rows (98 versus 101–109), the midbody scale rows (35 versus 41–43), and the total lamellae on one hand (30 versus 59–66).

Description of holotype. USNM 328158. A juvenile, based on the small SVL 30.7 mm (smaller than 25% of the largest SVL of the closest relative [ Celestus barbouri ]); tail nearly cylindrical, broken, 2.74 mm (8.93% SVL); axilla-to-groin distance 15.6 mm (50.8% SVL); forelimb length 6.58 mm (21.4% SVL); hindlimb length 9.20 mm (30.0% SVL); head length 5.99 mm (19.5% SVL); head width 4.69 mm (15.3% SVL); head width 78.3% head length; diameter of orbit 1.49 mm (4.85% SVL); horizontal diameter of ear opening 0.70 mm (2.28% SVL); vertical diameter of ear opening 0.55 mm (1.79% SVL); length of all toes on one foot 10.6 mm (34.5% SVL); shortest distance between angled subocular and lip 0.20 mm (0.651% SVL); shortest distance between the ocular and auricular openings 2.81 mm (9.15% SVL); longest finger length 1.58 mm (5.15% SVL); largest supraocular width 1.24 mm (4.04% SVL); cloacal width 2.75 mm (8.96% SVL); mental width 0.70 mm (2.28% SVL); postmental width 1.29 mm (4.20% SVL); prefrontal width 1.97 mm (6.42% SVL); frontal width 74.3% frontal length; nasal height 0.72 mm (2.35% SVL); angled subocular height 0.58 mm (1.89% SVL); shortest distance between the eye and naris 1.73 mm (5.64% SVL); canthal iii width 0.85 mm (2.77% SVL); angled subocular width 0.96 mm (3.13% SVL); nasal width 0.75 mm (2.44% SVL); rostral 2.11X as wide as high, visible from above, not in contact with nasals, in contact with 1 st supralabial and anterior internasal (left)/(right); anterior internasals are narrower than posterior ones; frontonasals and prefrontal fused into a single large plate with a slightly concave posterior margin, wider than long, bordered by posterior internasals, 1 st loreals, canthal iii, 1 st median oculars, and the frontal; frontal longer than wide; a pair of frontoparietals, separated by the posterior prolongation of the frontal and the interparietal plate; interparietal plate smaller than parietals and separating them, posteriorly touching the interoccipital, which is much wider than long; parietal separated from supraoculars by 1 st and 2 nd temporals and frontoparietal (left)/(right); nasal single; nostril above suture between 1 st and 2 nd supralabials (left)/(right); 1 postnasal (left)/(right); 2 loreals (left)/ (right); 1 st loreal higher than wide (left)/(right), in contact with postnasal, posterior internasal, prefrontal/frontonasal complex, canthal iii, 2 nd loreal, and the 3 rd –4 th supralabials (left)/(right); 2 nd loreal shorter than 1 st, approximately as high as wide (left)/(right), excluded from contact with supraocular by canthal iii (left)/(right); 2 nd loreal posteriorly bordering the lower preocular (left)/upper and lower preoculars (right); canthal iii wider than high (left)/(right), contacting 1 st median ocular, anterior supraciliary, upper and lower preoculars, prefrontal/frontonasal complex, and 1 st and 2 nd loreals (left)/(right); 9 median oculars (left)/(right), 1 st contacting the prefrontal (left)/(right); 1 upper preocular (left)/(right); an irregular anterior supraciliary (left)/(right); 5 (left)/6 (right) lateral oculars; 5 temporals (left)/(right); 2 suboculars (left)/(right); posterior subocular large and elongate (left)/(right); anterior subocular small (left)/(right); 9 (left)/8 (right) supralabials, 6 to level below center of eye (left)/(right); 8 infralabials (left)/(right), 6 (left)/(right) to level below center of eye; mental small, followed by a single, larger postmental; 4 pairs of enlarged chin shields; 1 st pair in contact with one another; 2 nd to 4 th pair separated by 1–2 scales; 100 transverse rows of dorsal scales from interoccipital to base of tail; 98 transverse rows of ventral scales from mental to vent; 35 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 7 lamellae under longest finger (left)/(right); 30 total lamellae on one hand; toe lengths 4>3>5>2>1; 12 (left)/11 (right) lamellae under longest toe; dorsal body and caudal scales striate with a small median keel; smooth ventral scales; 83 total strigae counted on ten scales.

Color (in alcohol): dorsal surface of head tan with the median supraorbital series outlined in darker brown; lateral surfaces of head grading from tan to cream with darker brown eye masks and markings on the labial scales; dorsal surfaces of the body are tan with longitudinal paramedian lines and darker flecks vaguely arranged into herring bones; dorsal surface of tail the same as the body; lateral areas grade from medium brown to cream; dorsal surfaces of the limbs are medium brown; lateral and ventral areas of the limbs fade from medium brown to cream; ventral surfaces of the head, body, and tail are cream with some lineate markings under the throat and chest.

FIGURE 32. (A–F) Celestus oligolepis sp. nov. (USNM 328158, holotype), SVL 30.7 mm.

Variation. No other specimens are known. Measurements and other morphological data for the holotype are presented in Table 1.

Distribution. Celestus oligolepis sp. nov. is known only from the holotype, which was collected on the southern coast of the western tip of Jamaica at “0 m” elevation in Westmoreland Parish (Fig. 11).

Ecology and conservation. Little is known of the ecology of this species other than the holotype was collected at dusk in sea grape leaf litter. The specimen was assumed to be a C. crusculus at the time it was collected and the habitat is unremarkable and disturbed as one might expect along the busy coastal road. Given the abundance of sympatric C. capitulatus sp. nov. (N = 36 examined), to the east and west along the coast, compared with this single specimen of C. oligolepis sp. nov., suggests that it is localized and rare.

We consider the conservation status of Celestus oligolepis sp. nov. to be Critically Endangered B1ab(iii), based on IUCN Redlist criteria ( IUCN 2023). It faces a primary threat from habitat destruction from agriculture and urbanization. Secondary threats include predation from introduced mammals, including the mongoose and black rats. Studies are needed to determine the health and extent of remaining populations and threats to the survival of the species. Captive-breeding programs should be undertaken, because eradication of introduced mammalian predators is not yet possible on Jamaica.

Reproduction. No data on reproduction are available for this species.

Etymology. The species name ( oligolepis ) is a Latin adjective meaning “few scales,” in reference to the low scale counts of this species.

Remarks. Because the only known representative is a juvenile, we only use morphological characters that are based on pattern and scale counts in our morphological diagnoses. Whereas C. jamesbondi and C. oligolepis cannot be morphologically separated based on our standard suite of characters, they can be morphologically separated based on the ratio of mental to vent scales by midbody scales (2.80 [n=1] versus 2.14–2.77 [n=35]).

Despite having only a single specimen, we are confident that it represents a distinct species because of its combination of morphological differences and large genetic divergence from other species. Celestus oligolepis sp. nov. is included in our genetic dataset and has support values of 57% and 54% at the node that places it as the closest relative of C. barbouri in our ML and Bayesian analyses, respectively. Based on our timetree (Fig. 4), Celestus oligolepis sp. nov. diverged from its closest relative 4.20 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). Celestus oligolepis sp. nov. was recognized as a distinct species by our ASAP analysis.