Celestus barbouri Grant, 1940a

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 40-44

Celestus barbouri Grant, 1940a

Jamaican Chevronate Forest Lizard

(Fig. 13–14)

Celestus barbouri Grant, 1940a:101 . Holotype: MCZ R-45169, collected by Chapman Grant from Mandeville between 13–15 April 1937 (18.04, -77.51).

Celestus barbouri — Cousens, 1956:2.

Celestus barbouri — Schwartz & Henderson, 1991:367.

Celestus barbouri — Hedges et al., 2019:16.

Celestus barbouri — Schools & Hedges, 2021:220.

Celestus barbouri — Landestoy et al., 2022:204.

Material examined (n=14). JAMAICA. Manchester. MCZ R-45169, Chapman Grant, Mandeville, 13–15 April 1937 ; USNM 38949–50 , Mandeville. Saint Elizabeth. BMNH 1936.12.1.110, Mr. J. Armitage, Springfield, 1936.

Trelawny. ANSP 38503 , S. Blair Hedges , Carla Ann Hass, Kimberlyn Nelson, and Stephen Schaeffer , 0.5 km N of Windsor, 28 February 1990 ; USNM 328145–47 , Minocal Stephenson , ca. 0.8 km N of Quick Step, 13 January 1984 ; USNM 328148 , Walton and Wayne Stephenson, vicinity of Quick Step , 29 September 1984 ; USNM 328149 , USNM 328151–3 , Minocal Stephenson and family, vicinity of Quick Step , 18–22 September 1985 . Unknown. One of two untagged specimens in one jar: BMNH 1965.234 or 1965.235 (Spur Tree, Manchester; or Mt. Diablo , Saint Ann, 1965) .

Diagnosis. Celestus barbouri has (1) a dorsal pattern of chevrons, (2) head markings absent/present, (3) markings in the longitudinal paramedian area absent, (4) dots arranged in bars in the lateral band absent, (5) an adult SVL of 78.4–93.6 mm, (6) ventral scale rows, 118–151, (7) midbody scale rows, 47–56, (8) total lamellae on one hand, 36–49, (9) total strigae on ten scales, 105–136, (10) relative length of all digits on one hindlimb, 18.2– 23.5 %, (11) relative distance between the angled subocular and mouth, 0.437 –0.556 %, (12) relative eye length, 2.87–3.63 %, (13) relative forelimb length, 15.4–19.0 %, (14) relative ear width, 0.810–1.86 %, (15) relative rostral height, 1.41–1.66 %, (16) relative head length, 14.6–16.6 %, (17) relative mental width, 1.51–1.85 %, (18) relative postmental width, 2.51–3.29 %, (19) relative cloacal width, 7.64–8.26 %, (20) relative prefrontal width, 3.97–4.33 %, (21) relative largest supraocular width, 1.92–2.74 %, (22) relative longest finger length, 2.92–3.81 %, (23) relative distance between the ear and eye, 6.23–7.15 %, (24) relative head width, 73.8–81.7 %, (25) relative frontal width, 65.6–82.1 %, (26) relative nasal height, 0.930–1.12 %, (27) relative angled subocular height, 0.553–1.16 %, (28) relative distance between the eye and naris, 4.68–4.83 %, (29) relative canthal iii length, 1.54–1.93 %, (30) relative angled subocular width, 1.97–2.52 %, and (31) relative nasal length, 1.38–1.65 %. The species stem time is 4.2 Ma and the species crown time is 0.26 Ma (Fig. 4).

We distinguish Celestus barbouri from the other species of Celestus based on a complex of traits. From Celestus capitulatus sp. nov., we distinguish C. barbouri by the dorsal pattern (chevrons versus irregular dots/dots in chevrons). From C. crusculus , we distinguish C. barbouri by the dorsal pattern (chevrons versus absent/flecks in series/dots in chevrons), the longitudinal paramedian lines (absent versus present), the adult SVL (78.4–93.6 versus 59.6–77.6), the ventral scale rows (118–151 versus 98–114), the midbody scale rows (47–56 versus 37–44), and the relative frontal width (65.6–82.1 versus 82.6–91.1). From C. duquesneyi , we distinguish C. barbouri by the dorsal pattern (chevrons versus bands), the adult SVL (78.4–93.6 versus 62.1), the total lamellae on one hand (36–49 versus 64), the relative length of digits on one hindlimb (18.2–23.5 versus 31.4), the relative distance between angled subocular and mouth (0.437 –0.556 versus 0.644), the relative eye length (2.87–3.63 versus 4.36), the relative forelimb length (15.4–19.0 versus 24.4), the relative ear width (0.810–1.86 versus 2.45), the relative rostral height (1.41–1.66 versus 2.14), the relative head length (14.6–16.6 versus 21.6), the relative mental width (1.51–1.85 versus 2.35), the relative cloacal width (7.64–8.26 versus 9.98), the relative prefrontal width (3.97–4.33 versus 5.41), the relative longest finger length (2.92–3.81 versus 6.52), the relative distance between the ear and eye (6.23–7.15 versus 7.68), the relative head width (73.8–81.7 versus 64.6), the relative angled subocular height (0.553–1.16 versus 1.61), the relative distance between the eye and naris (4.68–4.83 versus 5.46), the relative angled subocular width (1.97–2.52 versus 2.90), and the relative nasal width (1.38–1.65 versus 2.01). From C. hesperius sp. nov., we distinguish C. barbouri by the dorsal pattern (chevrons versus dots in chevrons), the adult SVL (78.4– 93.6 versus 54.0–62.3), the ventral scale rows (118–151 versus 111–114), the midbody scale rows (47–56 versus 39–44), the total lamellae on one hand (36–49 versus 29–34), the relative distance between angled subocular and mouth (0.437 –0.556 versus 0.594 –0.648), and the relative prefrontal width (3.97–4.33 versus 4.65–5.02). From C. hewardi , we distinguish C. barbouri by the dorsal pattern (chevrons versus mottled/bands), the adult SVL (78.4– 93.6 versus 129–171), the total lamellae on one hand (36–49 versus 50–61), the total strigae on ten scales (105–136 versus 164–315), the relative length of digits on one hindlimb (18.2–23.5 versus 24.1–30.6), the relative distance between angled subocular and mouth (0.437 –0.556 versus 0.744–1.40), the relative forelimb length (15.4–19.0 versus 22.2–24.6), the relative head length (14.6–16.6 versus 16.8–21.5), the relative cloacal width (7.64–8.26 versus 8.81–9.89), the relative longest finger length (2.92–3.81 versus 5.03–5.66), the relative nasal height (0.930– 1.12 versus 1.21–1.24), and the relative distance between the eye and naris (4.68–4.83 versus 5.00–5.60). From C. jamesbondi sp. nov., we distinguish C. barbouri by the dorsal pattern (chevrons versus absent/irregular dots/dots in chevrons), the adult SVL (78.4–93.6 versus 54.7–72.0), the ventral scale rows (118–151 versus 91–112), and the midbody scale rows (47–56 versus 35–44). From C. macrolepis , we distinguish C. barbouri by the dorsal pattern (chevrons versus bicolored), the adult SVL (78.4–93.6 versus 254–316), the ventral scale rows (118–151 versus 112–116), the total lamellae on one hand (36–49 versus 52–54), the total strigae on ten scales (105–136 versus 398), the relative length of digits on one hindlimb (18.2–23.5 versus 27.5–28.0), the relative distance between angled subocular and mouth (0.437 –0.556 versus 1.39–1.66), the relative forelimb length (15.4–19.0 versus 26.1–26.7), the relative head length (14.6–16.6 versus 19.2–22.9), the relative mental width (1.51–1.85 versus 1.87), the relative postmental width (2.51–3.29 versus 3.81), the relative cloacal width (7.64–8.26 versus 11.2), the relative prefrontal width (3.97–4.33 versus 3.94), the relative longest finger length (2.92–3.81 versus 5.47–5.51), the relative distance between the ear and eye (6.23–7.15 versus 8.02–10.9), the relative nasal height (0.930–1.12 versus 1.18), the relative angled subocular height (0.553–1.16 versus 1.17), the relative distance between the eye and naris (4.68–4.83 versus 6.02), the relative width of canthal iii (1.54–1.93 versus 1.99), the relative angled subocular width (1.97–2.52 versus 2.57), and the relative nasal width (1.38–1.65 versus 1.75). From C. macrotus , we distinguish C. barbouri by the longitudinal paramedian lines (absent versus present), the dots arranged in bars in the lateral areas (absent versus present), the ventral scale rows (118–151 versus 87–93), the midbody scale rows (47–56 versus 41–45), the relative length of digits on one hindlimb (18.2–23.5 versus 30.2–31.2), the relative distance between angled subocular and mouth (0.437 –0.556 versus 0.640 –0.983), the relative eye length (2.87–3.63 versus 3.79–5.17), the relative forelimb length (15.4–19.0 versus 22.4–25.0), the relative head length (14.6–16.6 versus 18.2–20.5), the relative prefrontal width (3.97–4.33 versus 4.87–5.55), the relative largest supraocular width (1.92–2.74 versus 2.96–4.03), the relative longest finger length (2.92–3.81 versus 6.43–6.67), the relative distance between the ear and eye (6.23–7.15 versus 7.58–8.02), the relative nasal height (0.930–1.12 versus 1.15–1.62), the relative distance between the eye and naris (4.68–4.83 versus 5.48–5.60), the relative angled subocular width (1.97–2.52 versus 2.77–2.83), and the relative nasal width (1.38–1.65 versus 2.08–2.33). From C. microblepharis , we distinguish C. barbouri by the adult SVL (78.4–93.6 versus 96.4), the ventral scale rows (118–151 versus 109), the midbody scale rows (47–56 versus 43), the total lamellae on one hand (36–49 versus 30), the total strigae on ten scales (105–136 versus 165), the relative length of digits on one hindlimb (18.2–23.5 versus 16.6), the relative distance between angled subocular and mouth (0.437 –0.556 versus 0.820), the relative eye length (2.87–3.63 versus 1.83), the relative forelimb length (15.4–19.0 versus 14.2), the relative ear width (0.810–1.86 versus 0.446), the relative rostral height (1.41–1.66 versus 1.71), the relative mental width (1.51–1.85 versus 1.44), the relative postmental width (2.51–3.29 versus 2.47), the relative prefrontal width (3.97–4.33 versus 4.37), the relative nasal height (0.930–1.12 versus 0.726), the relative angled subocular width (1.97–2.52 versus 2.90), and the relative nasal width (1.38–1.65 versus 1.11). From C. molesworthi , we distinguish C. barbouri by the dorsal pattern (chevrons versus dots in chevrons), the total strigae on ten scales (105–136 versus 138–159), the relative distance between angled subocular and mouth (0.437 –0.556 versus 0.653 – 0.845), the relative rostral height (1.41–1.66 versus 1.72–1.81), the relative head length (14.6–16.6 versus 17.2– 20.0), the relative cloacal width (7.64–8.26 versus 8.73–9.35), the relative prefrontal width (3.97–4.33 versus 4.44– 4.90), the relative longest finger length (2.92–3.81 versus 4.28–5.19), the relative distance between the ear and eye (6.23–7.15 versus 7.97–8.83), the relative nasal height (0.930–1.12 versus 1.17–1.26), the relative distance between the eye and naris (4.68–4.83 versus 5.32–5.50), and the relative width of canthal iii (1.54–1.93 versus 1.99–2.09). From C. occiduus , we distinguish C. barbouri by the dorsal pattern (chevrons versus absent), the adult SVL (78.4– 93.6 versus 269–367), the total lamellae on one hand (36–49 versus 50–66), the total strigae on ten scales (105–136 versus 374), the relative length of digits on one hindlimb (18.2–23.5 versus 24.4–29.7), the relative distance between angled subocular and mouth (0.437 –0.556 versus 1.26–1.27), the relative forelimb length (15.4–19.0 versus 23.5– 23.9), the relative head length (14.6–16.6 versus 20.4–20.6), the relative mental width (1.51–1.85 versus 1.86), the relative postmental width (2.51–3.29 versus 3.57), the relative cloacal width (7.64–8.26 versus 9.00), the relative prefrontal width (3.97–4.33 versus 4.76), the relative longest finger length (2.92–3.81 versus 4.77–5.46), the relative distance between the ear and eye (6.23–7.15 versus 8.98–10.9), the relative frontal width (65.6–82.1 versus 63.8), the relative nasal height (0.930–1.12 versus 1.16), the relative angled subocular height (0.553–1.16 versus 1.3), the relative distance between the eye and naris (4.68–4.83 versus 6.51), and the relative nasal width (1.38–1.65 versus 1.83). From C. oligolepis sp. nov., we distinguish C. barbouri by the dorsal pattern (chevrons versus dots in chevrons), the longitudinal paramedian lines (absent versus present), the ventral scale rows (118–151 versus 98), the midbody scale rows (47–56 versus 35), and the total lamellae on one hand (36–49 versus 30). From C. striatus , we distinguish C. barbouri by the adult SVL (78.4–93.6 versus 145), the ventral scale rows (118–151 versus 101–109), the midbody scale rows (47–56 versus 41–43), the total lamellae on one hand (36–49 versus 59–66), the total strigae on ten scales (105–136 versus 279), the relative length of digits on one hindlimb (18.2–23.5 versus 37.8), the relative distance between angled subocular and mouth (0.437 –0.556 versus 0.710), the relative eye length (2.87– 3.63 versus 3.85), the relative forelimb length (15.4–19.0 versus 26.1), the relative rostral height (1.41–1.66 versus 1.94), the relative head length (14.6–16.6 versus 18.9), the relative prefrontal width (3.97–4.33 versus 5.68), the relative longest finger length (2.92–3.81 versus 7.48), the relative distance between the ear and eye (6.23–7.15 versus 9.00), the relative head width (73.8–81.7 versus 82.1), the relative distance between the eye and naris (4.68– 4.83 versus 6.16), and the relative width of canthal iii (1.54–1.93 versus 2.12).

Description of holotype. MCZ R-45169. An adult; SVL 66.6 mm; tail nearly cylindrical, broken, 12.9 mm (19.4% SVL); axilla-to-groin distance 36.4 mm (54.7% SVL); forelimb length 13.3 mm (20.0% SVL); hindlimb length 20.6 mm (30.9% SVL); head length 11.8 mm (17.7% SVL); head width 9.56 mm (14.4% SVL); head width 81.0% head length; diameter of orbit 2.14 mm (3.21% SVL); horizontal diameter of ear opening 1.11 mm (1.67% SVL); vertical diameter of ear opening 1.24 mm (1.86% SVL); length of all toes on one foot 15.6 mm (23.4% SVL); shortest distance between angled subocular and lip 0.61 mm (0.916% SVL); shortest distance between the ocular and auricular openings 5.00 mm (7.51% SVL); longest finger length 2.95 mm (4.43% SVL); largest supraocular width 3.96 mm (5.95% SVL); cloacal width 6.00 mm (9.01% SVL); mental width 1.28 mm (1.92% SVL); postmental width 2.35 mm (3.53% SVL); prefrontal width 5.99 mm (8.99% SVL); frontal width 83.9% frontal length; nasal height 1.76 mm (2.64% SVL); angled subocular height 0.66 mm (0.991% SVL); shortest distance between the eye and naris 4.47 mm (6.71% SVL); canthal iii width 1.25 mm (1.88% SVL); angled subocular width 1.43 mm (2.15% SVL); nasal width 1.11 mm (1.67% SVL); rostral 1.65X as wide as high, barely 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 concave posterior margin, much wider than long, bordered by posterior internasals, 1 st loreals, 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 approximately the size of 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, 1 st median ocular, canthal iii, 2 nd loreal, and 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); final loreal posteriorly bordering the lower preocular (left)/(right); canthal iii wider than high (left)/(right), contacting 1 st median ocular, anterior supraciliary, upper and lower preoculars, 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); 6 lateral oculars (left)/(right); 5 temporals (left)/(right); 3 suboculars (left)/(right); posterior subocular large and elongate (left)/(right); anterior suboculars small (left)/(right); 9 supralabials (left)/(right), 6 to level below center of eye (left)/(right); 8 (left)/9 (right) infralabials, 6 to level below center of eye (left)/(right); mental small, followed by a single, larger postmental; 4 pairs of enlarged chin shields; 1 st pair in contact with one another; 2 nd –4 th pairs separated by 1–4 scales; 136 transverse rows of dorsal scales from interoccipital to base of tail; 131 transverse rows of ventral scales from mental to vent; 50 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 9 lamellae under longest finger (left)/(right); 36 total lamellae on one hand; toe lengths 4>3>5>2>1; 14 (left)/15 (right) lamellae under longest toe; strigae and a faint median keel dorsal body and caudal scales; smooth to faintly striated ventral scales; 82 total strigae counted on ten scales.

FIGURE 13. (A–F) Celestus barbouri (MCZ R-45169, holotype), SVL 66.6 mm.

Color (in alcohol): dorsal surface of head medium tan and patternless; lateral surfaces of head grading from medium tan to orange-cream with some faded brown areas around the eyes and on the labial scales; dorsal surfaces of the body are medium brown with darker brown chevrons; dorsal surface of tail is golden brown with the chevrons of the body disappearing after the base; lateral areas are medium brown with white spots vaguely arranged in vertical lines; dorsal surfaces of the limbs are medium brown with a few paler gold spots; lateral and ventral areas of the limbs fade to dark cream; ventral surfaces of the head, body, and tail are dark cream and patternless other than a few faded brown areas on the chin shields.

Variation. The examined material resembles the pattern of the holotype closely with chevrons extending down the dorsum. In ANSP 38503 , the chevrons become reduced posteriorly. ANSP 38503 also exhibits very faint black outlines on the head scales and lacks longitudinal paramedian markings. Measurements and other morphological data for the holotype and other examined material are presented in Table 1 .

Distribution. Celestus barbouri is distributed in the north central region of Jamaica at elevations of 100–610 m (Fig. 11).

FIGURE 14. Celestus barbouri (USNM 328151, SBH 161120), SVL 78.4 mm, in life. From Quick Step, Trelawny Parish, Jamaica. Photo by SBH.

Ecology and conservation. Little information is available on the ecology of this species. Individuals have been seen in “trash” (rotting vegetation) piles ( Grant 1940a), in rotting coconut debris in a dry scrub forest ( Underwood 1959), and in open areas around a cultivated sinkhole ( Schwartz & Henderson 1991). The natural habitat of the species is assumed to be the primary forest (limestone forest) adjacent to these disturbed areas where collections were made (see Materials and Methods). This species is rarely encountered (SBH), possibly because of habitat destruction or introduced predators or both. Two large adults weighed 7.0 and 10.8 g (SBH).

The IUCN Redlist ( IUCN 2023) considers the conservation status of Celestus barbouri to be Endangered B1ab(i,iii,v) because “the species has an extent of occurrence of 3,125 km 2, and occurs in a single location defined by a widespread threat from the invasive Small Asian Mongoose, within which the extent and quality of habitat— and it is suspected the number of mature individuals—is declining.” 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 refers to Thomas Barbour, herpetologist and director of the Museum of Comparative Zoology at Harvard at the time of description in 1940.

Remarks. Celestus barbouri has been confused with C. impressus ( Grant 1940a) , which we consider a synonym of C. hewardi (see below). Celestus barbouri was included in our genetic dataset and has significant support in both Bayesian and ML likelihood analyses at the crown node (two samples from the Cockpits in Trelawny). Celestus barbouri was identified as the closest relative to C. oligolepis sp. nov. in both our ML and Bayesian analyses; however, this relationship was not significant in either analysis (support values of 57% and 54%, respectively). Using genetic data, Schools et al. (2022) considered C. barbouri the closest relative of C. oligolepis sp. nov. with a support value of 83% in ML analyses and 89% analyses. Based on our timetree (Fig. 4), C. barbouri diverged from its closest relative 4.20 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). Remarkably, C. barbouri is separated from C. capitulatus sp. nov. in our morphological data set only by dorsal pattern, yet the two are deeply divergent genetically (Figs. 3–4) and are not closest relatives. This is remarkable because the two have not been confused previously, in that the material of C. capitulatus sp. nov. was identified as C. crusculus , not C. barbouri , in the past. It probably reflects the fact that morphological data sets in taxonomy, even large ones, never encompass the entire phenotype. Celestus barbouri was recognized as a distinct species by our ASAP analysis.