Comptus badius ( Cope 1868 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 114-118

Comptus badius ( Cope 1868)

Navassa Forest Lizard

(Fig. 39–40)

Celestus badius Cope, 1868:126 . Syntypes: USNM 25817–8, collected by W. J. Rasin on Navassa Island (18.4, -75.0). Celestus badius — Barbour, 1930:99.

Celestus badius — Barbour, 1935:123.

Celestus badius — Barbour, 1937:139.

Diploglossus badius — Schwartz, 1964:38.

Celestus costatus badius — Schwartz & Henderson, 1988:94.

Celestus badius — Powell, 1999:4.

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

Comptus badius — Schools & Hedges, 2021:226.

Comptus badius — Landestoy et al., 2022: 205.

Material examined (n=6). NAVASSA ISLAND. AMNH 17079 , Rollo H. Beck, 1917 ; AMNH 120486 , Craig Ferris, July 1981 ; AMNH 120487 , Craig Ferris , 20 July 1981 ; USNM 25817–8 , W. J. Rasin ; USNM 157378 .

Diagnosis. Comptus badius has (1) a dorsal pattern of irregular dots/mottled, (2) head markings absent/present, (3) markings in the longitudinal paramedian area present, (4) dots arranged in bars in the lateral band absent/present, (5) an adult SVL of 78.2–99.1 mm, (6) ventral scale rows, 94–109, (7) midbody scale rows, 39–44, (8) total lamellae on one hand, 40–45, (9) total strigae on ten scales, 203–241, (10) relative length of all digits on one hindlimb, 23.4–33.9 %, (11) relative distance between the angled subocular and mouth, 0.403 –0.866 %, (12) relative eye length, 2.83–3.53 %, (13) relative forelimb length, 19.6–23.0 %, (14) relative ear width, 1.34–1.75 %, (15) relative rostral height, 1.83–2.42 %, (16) relative head length, 14.7–18.3 %, (17) relative mental width, 1.38 %, (18) relative postmental width, 2.39 %, (19) relative cloacal width, 7.92–9.30 %, (20) relative prefrontal width, 4.59–5.47 %, (21) relative largest supraocular width, 2.57–2.74 %, (22) relative longest finger length, 4.38–5.04 %, (23) relative distance between the ear and eye, 6.99–9.51 %, (24) relative head width, 62.8–69.3 %, (25) relative frontal width, 71.3–86.5 %, (26) relative nasal height, 0.999–1.06 %, (27) relative angled subocular height, 0.691–1.33 %, (28) relative distance between the eye and naris, 4.96–5.24 %, (29) relative canthal iii length, 1.45–2.42 %, (30) relative angled subocular width, 1.91–2.31 %, and (31) relative nasal length, 1.54–1.82 %. The species stem time is 3.52 Ma and the species crown time is 0.0 Ma (Fig. 4).

Comptus badius has a smaller relative head width than all other species of the genus (62.8–69.3). Notably, this species also has the most reduced keels (to the point of complete absence) of the genus.

From Comptus alloeides , we distinguish C. badius by the adult SVL (78.2–99.1 versus 124–161), the relative postmental width (2.39 versus 2.54–2.97), the relative longest finger length (4.38–5.04 versus 5.32–5.95), and the relative head width (62.8–69.3 versus 70.0–74.2). From C. arboreus sp. nov., we distinguish C. badius by the dorsal pattern (irregular dots/mottled versus dots in series/dots in chevrons), the total lamellae on one hand (40–45 versus 48–54), the relative length of digits on one hindlimb (23.4–33.9 versus 37.4–39.7), the relative forelimb length (19.6–23.0 versus 24.1–25.3), the relative mental width (1.38 versus 1.54–1.74), the relative postmental width (2.39 versus 2.95–3.01), the relative longest finger length (4.38–5.04 versus 6.01–6.37), the relative head width (62.8– 69.3 versus 71.7–80.3), and the relative angled subocular width (1.91–2.31 versus 2.82–3.28). From C. maculatus , we distinguish C. badius by the dorsal pattern (irregular dots/mottled versus absent/chevrons), the total lamellae on one hand (40–45 versus 32–37), the total strigae on ten scales (203–241 versus 149–201), the relative mental width (1.38 versus 1.69–1.85), and the relative head width (62.8–69.3 versus 69.6–80.0). From C. stenurus , we distinguish C. badius by the dorsal pattern (irregular dots/mottled versus dots in series/dots in chevrons), the adult SVL (78.2– 99.1 versus 121–146), the total lamellae on one hand (40–45 versus 47–57), the relative mental width (1.38 versus 1.52–1.78), the relative postmental width (2.39 versus 2.61–3.05), the relative longest finger length (4.38–5.04 versus 5.89–7.19), and the relative head width (62.8–69.3 versus 70.2–74.2). From C. weinlandi , we distinguish C. badius by the adult SVL (78.2–99.1 versus 101–133), the relative mental width (1.38 versus 1.41–1.90), the relative postmental width (2.39 versus 2.57–2.91), the relative longest finger length (4.38–5.04 versus 5.08–6.31), and the relative head width (62.8–69.3 versus 73.6–82.2).

Description of syntype. USNM 25818. An adult; SVL 99.1 mm; tail nearly cylindrical, broken, 9.15 mm (9.23% SVL); axilla-to-groin distance 55.7 mm (56.2% SVL); forelimb length 19.7 mm (19.9% SVL); hindlimb length 29.4 mm (29.7% SVL); head length 18.0 mm (18.2% SVL); head width 11.3 mm (11.4% SVL); head width 62.8% head length; diameter of orbit 3.40 mm (3.43% SVL); horizontal diameter of ear opening 1.67 mm (1.69% SVL); vertical diameter of ear opening 1.57 mm (1.58% SVL); length of all toes on one foot 27.1 mm (27.3% SVL); shortest distance between angled subocular and lip 0.61 mm (0.616% SVL); shortest distance between the ocular and auricular openings 7.84 mm (7.91% SVL); longest finger length 4.99 mm (5.04% SVL); largest supraocular width 2.72 mm (2.74% SVL); cloacal width 9.22 mm (9.30% SVL); prefrontal width 4.93 mm (4.97% SVL); frontal width 77.3% frontal length; nasal height 0.99 mm (1.00% SVL); angled subocular height 1.32 mm (1.33% SVL); shortest distance between the eye and naris 5.19 mm (5.24% SVL); canthal iii width 1.44 mm (1.45% SVL); angled subocular width 2.29 mm (2.31% SVL); nasal width 1.53 mm (1.54% SVL); rostral 2.42X 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 concave posterior margin, much wider than long, bordered by posterior internasals, 1 st loreals, canthal iii, 1 st median ocular (and 2 nd on the right), 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 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 upper and lower preoculars (left)/(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 (left)/10 (right) median oculars, 1 st contacting the prefrontal (left)/1 st and 2 nd (right); 1 upper preocular (left)/(right); an irregular anterior supraciliary (left)/(right); 6 (left)/5 (right) lateral oculars; 5 temporals (left)/(right); 2 suboculars (left)/(right); posterior subocular large and elongate (left)/(right); anterior subocular small (left)/(right); 8 supralabials (left)/(right), 5 to level below center of eye (left)/(right); 9 infralabials (left)/(right), 5 (left)/5–6(right) to level below center of eye; mental small, followed by a single, larger post mental; 4 pairs of enlarged chin shields; 1 st pair in contact with one another; 2 nd –4 th pairs separated by 1–3 scales; 100 transverse rows of dorsal scales from interoccipital to base of tail; 97 transverse rows of ventral scales from mental to vent; 42 scales around midbody; 5 digits; finger lengths 4>3>2>5>1; 12 (left)/11 (right) lamellae under longest finger; 43 total lamellae on one hand; toe lengths 4>3>5>2>1; 20 lamellae under longest toe (left)/(right); keelless and striate dorsal body and caudal scales; smooth ventral scales; 227 total strigae counted on ten scales.

Color (in alcohol): dorsal surface of head pale tan, patternless; lateral surfaces of head grading from pale tan to creamy yellow with pale brown eye masks; dorsal surfaces of the body are pale tan with faded darker brown markings near the hindlimbs; dorsal surface of tail the same as the body; lateral areas grade from medium brown to creamy yellow with faded, paler mottling; dorsal surfaces of the limbs are medium brown with some paler mottling; lateral and ventral areas of the limbs fade to creamy yellow, patternless; ventral surfaces of the head, body, and tail are creamy yellow, patternless.

Variation. The other material examined was less faded than the syntypes. In all other specimens examined a similar pattern was expressed of dots or mottling down the dorsum and present longitudinal paramedian lines. In AMNH 17079 the dots in the lateral band appeared as bars whereas in the other specimens examined this trait was expressed as mottling. Measurements and other morphological data for the holotype and other examined material are presented in Table 1 .

FIGURE 39. (A–F) Comptus badius (USNM 25818, syntype), SVL 99.1 mm.

FIGURE 40. Comptus badius (SBH 194991), in life. From Navassa Island, United States. Photo by SBH.

Distribution. Comptus badius is distributed on Navassa Island where it has been collected at elevations from near sea level to 70 m (Fig. 35).

Ecology and conservation. No ecological information is associated with the types. However, authors have commented that this species was common on Navassa Island ( Thomas 1966; Powell 1999). Thomas (1966) noted that this species was often observed “scurrying” in dead leaves, although he thought this behavior might have been because of the end of the dry season. Powell (1999) also noticed this species abundantly in leaf litter. Powell (1999) noted that he observed Comptus badius as early as sunrise but that they became most abundant at 0930–1000 h and stayed active until twilight. Thomas (1966) noted abundant juveniles and gravid females in April. Powell (1999) also noted that juveniles were common when he visited the island in late summer (with several small individuals collected in pitfall traps), leading him to believe that the species had an extended breeding season on Navassa Island, or potentially a bimodal breeding season, peaking both in April and late summer.

Comptus badius has been seen in grassy savannahs, near former human settlements, and climbing rock walls, likely to bask ( Powell 1999). A large male was recovered with a partially swallowed earthworm, suggesting that the diet of these lizards consists largely of leaf litter-dwelling invertebrates ( Powell 1999). Powell (1999) also studied the differences between the cloacal temperatures of C. badius and the corresponding surface temperatures. The cloacal temperatures of two adult lizards were 31.4°C and 32.3°C when taken at 1130 and 1500 h. Cloacal temperatures and the surface temperatures differed little, suggesting that the lizards could thermoconform ( Powell 1999). As surface temperatures and deep ground litter temperatures differed, Powell (1999) speculated that the lizards could regulate their body temperatures by moving to different litter depths.

The IUCN Redlist ( IUCN 2023) considers the conservation status of Comptus badius to be Least Concern because “although the distribution is limited (with an extent of occurrence of 5.28 km 2), the population appears to be stable, there are no current threats, and Navassa is a protected area.”

Reproduction. Ovoviviparous. Many gravid females and juveniles were recorded in August ( Thomas 1966); Additional juveniles were described as being abundant in late July–early August ( Powell 1999).

Etymology. The species name is Latin and translates to “brown” or “chestnut-colored,” presumably in reference to the dorsal color of this species.

Remarks. Because of a lack of fresh material, morphological similarities, and relationships between the fauna of Hispaniola and Navassa Island, Schwartz (1964) said “it seems not inappropriate” to consider Comptus badius as a subspecies of Panolopus costatus ( Celestus costatus badius ). Comptus badius was reelevated to a full species by Powell (1999) based on morphological differences and geographic isolation.

Comptus badius is included in our genetic dataset and we show that it is a member of Comptus , not Panolopus as was once thought when it was treated as a subspecies of “ Celestus ” (= Panolopus ) costatus ( Schwartz 1964) . It has significant support in both Bayesian and ML likelihood analyses at the crown node and the stem node places it outside of C. alloeides , C. maculatus , and C. weinlandi . Based on our timetree (Fig. 4), C. badius diverged from its closest relative 3.52 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). Comptus badius was recognized as a distinct species by our ASAP analysis.