Panolopus unicolor, 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 : 217-223

Panolopus unicolor sp. nov.

Unicolored Forest Lizard

(Fig. 79)

Panolopus curtissi hylonomus — Schools & Hedges, 2021:250 (part).

Panolopus curtissi hylonomus — Schools et al. 2022:42 (part).

Panolopus curtissi hylonomus — Landestoy et al., 2022: 222 (part).

Holotype. ANSP 38647 , an adult from 14.8 N, 7.8 km SE Cruce de Ocoa on dirt road, at Martinez, near La Palma, San José de Ocoa province, Dominican Republic, collected by Richard Thomas, Manuel Leal, and Herman Dominici on 10 July 1993 (18.46, -70.45; 675 m).

Diagnosis. Panolopus unicolor sp. nov. has (1) a dorsal pattern of absent, (2) head markings absent, (3) markings in the longitudinal paramedian area present, (4) dots arranged in bars in the lateral band present, (5) an adult SVL of 67.6 mm, (6) ventral scale rows, 93, (7) midbody scale rows, 40, (8) total lamellae on one hand, 48, (9) total strigae on ten scales, 144, (10) relative length of all digits on one hindlimb, 36.8 %, (11) relative distance between the angled subocular and mouth, 0.533 %, (12) relative eye length, 3.38 %, (13) relative forelimb length, 23.5 %, (14) relative ear width, 1.60 %, (15) relative rostral height, 2.23 %, (16) relative head length, 17.8 %, (17) relative mental width, 1.73 %, (18) relative postmental width, 2.80 %, (19) relative cloacal width, 7.61 %, (20) relative prefrontal width, 4.69 %, (21) relative largest supraocular width, 3.12 %, (22) relative longest finger length, 6.65 %, (23) relative distance between the ear and eye, 7.61 %, (24) relative head width, 70.8 %, (25) relative frontal width, 58.2 %, (26) relative nasal height, 1.15 %, (27) relative angled subocular height, 0.814 %, (28) relative distance between the eye and naris, 5.52 %, (29) relative canthal iii length, 1.79v, (30) relative angled subocular width, 2.90 %, and (31) relative nasal length, 2.00 %. The species stem time is 0.85 Ma and no data are available to estimate the species crown time (Fig. 4).

FIGURE 79. (A–F) Panolopus unicolor sp. nov. (ANSP 38647, holotype), SVL 67.6 mm.

Panolopus unicolor sp. nov. has a smaller relative frontal width (58.2) and a lower number of total strigae on ten scales (144) than most species of the genus. The species also has a larger relative length of digits on one hindlimb (36.8) than most species of the genus. The only known specimen of P. unicolor sp. nov. is a small adult specimen, which may contribute to a bias towards larger measurements. From Panolopus aenetergum , we distinguish P. unicolor sp. nov. by the dorsal pattern (absent versus irregular dots), the longitudinal paramedian lines (present versus absent), the total strigae on ten scales (144 versus 267), and the relative frontal width (58.2 versus 88.2). From P. aporus , we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 77.8–100), the total strigae on ten scales (144 versus 150–235), the relative length of digits on one hindlimb (36.8 versus 27.7–33.7), the relative cloacal width (7.61 versus 7.92–8.86), the relative prefrontal width (4.69 versus 4.18–4.53), the relative longest finger length (6.65 versus 4.57–5.72), the relative head width (70.8 versus 71.4–83.2), the relative frontal width (58.2 versus 61.7–75.1), the relative distance between the eye and naris (5.52 versus 4.69–5.44), the relative width of canthal iii (1.79 versus 1.85–1.96), the relative angled subocular width (2.90 versus 2.32–2.73), and the relative nasal width (2.00 versus 1.56–1.78). From P. chalcorhabdus , we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 71.9–95.4), the total strigae on ten scales (144 versus 184–233), the relative length of digits on one hindlimb (36.8 versus 31.3–36.0), the relative cloacal width (7.61 versus 7.74–9.08), the relative largest supraocular width (3.12 versus 2.52–2.86), the relative frontal width (58.2 versus 62.5–80.8), the relative width of canthal iii (1.79 versus 1.98–2.05),and the relative angled subocular width (2.90 versus 2.36–2.71). From P. costatus , we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 83.6–107), the total lamellae on one hand (48 versus 49–58), the total strigae on ten scales (144 versus 158–217), the relative distance between angled subocular and mouth (0.533 versus 0.582 –0.916), the relative prefrontal width (4.69 versus 3.97–4.67), the relative largest supraocular width (3.12 versus 1.93–3.01), the relative distance between the eye and naris (5.52 versus 5.08–5.50), the relative width of canthal iii (1.79 versus 1.82–1.90), the relative angled subocular width (2.90 versus 2.36–2.81), and the relative nasal width (2.00 versus 1.58–1.74). From P. curtissi , we distinguish P. unicolor sp. nov. by the dots arranged in bars in the lateral areas (present versus absent), the midbody scale rows (40 versus 32–38), the total lamellae on one hand (48 versus 32–39), the total strigae on ten scales (144 versus 165–260), the relative length of digits on one hindlimb (36.8 versus 20.8–28.1), the relative forelimb length (23.5 versus 15.1–20.5), the relative postmental width (2.80 versus 2.07–2.72), the relative prefrontal width (4.69 versus 3.96–4.68), the relative largest supraocular width (3.12 versus 1.88–2.98), the relative longest finger length (6.65 versus 3.59–4.54), the relative frontal width (58.2 versus 65.4–83.1), the relative distance between the eye and naris (5.52 versus 4.02–5.03), the relative angled subocular width (2.90 versus 2.26–2.76), and the relative nasal width (2.00 versus 1.44–1.82). From P. diastatus , we distinguish P. unicolor sp. nov. by the longitudinal paramedian lines (present versus absent), the midbody scale rows (40 versus 33–39), the total lamellae on one hand (48 versus 35–41), the total strigae on ten scales (144 versus 169–234), the relative length of digits on one hindlimb (36.8 versus 21.5–27.4), the relative eye length (3.38 versus 2.71–3.32), the relative forelimb length (23.5 versus 16.2–20.1), the relative ear width (1.60 versus 0.667–1.43), the relative prefrontal width (4.69 versus 3.74–4.61), the relative largest supraocular width (3.12 versus 1.88–2.57), the relative longest finger length (6.65 versus 3.48–4.87), the relative distance between the eye and naris (5.52 versus 4.06–4.94), the relative angled subocular width (2.90 versus 1.93–2.86), and the relative nasal width (2.00 versus 1.41–1.77). From P. emys , we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 99.0–113), the total strigae on ten scales (144 versus 238–311), the relative length of digits on one hindlimb (36.8 versus 28.9–35.2), the relative forelimb length (23.5 versus 18.5–23.4), the relative cloacal width (7.61 versus 8.24–8.96), the relative prefrontal width (4.69 versus 3.99–4.36), the relative largest supraocular width (3.12 versus 2.01–2.89), the relative longest finger length (6.65 versus 5.15–5.83), the relative head width (70.8 versus 71.1– 78.7), the relative frontal width (58.2 versus 67.7–74.5), the relative nasal height (1.15 versus 0.963–1.10), the relative distance between the eye and naris (5.52 versus 4.37–5.19). From P. hylonomus , we distinguish P. unicolor sp. nov. by the dots arranged in bars in the lateral areas (present versus absent), the midbody scale rows (40 versus 33–39), the total lamellae on one hand (48 versus 34–47), the total strigae on ten scales (144 versus 169–222), the relative length of digits on one hindlimb (36.8 versus 22.8–28.2), the relative forelimb length (23.5 versus 17.1– 20.7), the relative cloacal width (7.61 versus 7.98–8.57), the relative largest supraocular width (3.12 versus 2.65– 2.90), the relative longest finger length (6.65 versus 4.47–5.27), the relative head width (70.8 versus 73.8–76.4), the relative frontal width (58.2 versus 64.0–74.5), the relative distance between the eye and naris (5.52 versus 4.03– 4.98), the relative width of canthal iii (1.79 versus 1.95–2.03), and the relative angled subocular width (2.90 versus 1.61–2.75). From P. lanceolatus sp. nov., we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 78.5– 104), the total strigae on ten scales (144 versus 186–234), the relative length of digits on one hindlimb (36.8 versus 28.4–35.9), the relative distance between angled subocular and mouth (0.533 versus 0.567 –0.704), the relative ear width (1.60 versus 0.770–1.35), the relative postmental width (2.80 versus 2.36–2.66), the relative cloacal width (7.61 versus 8.01–8.76), the relative prefrontal width (4.69 versus 3.97–4.55), the relative largest supraocular width (3.12 versus 2.20–2.71), the relative longest finger length (6.65 versus 4.76–6.36), the relative frontal width (58.2 versus 63.1–72.1), the relative nasal height (1.15 versus 0.904–1.06), the relative distance between the eye and naris (5.52 versus 4.58–5.05), and the relative nasal width (2.00 versus 1.48–1.95). From P. lapierrae sp. nov., we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 72.6–88.3), the midbody scale rows (40 versus 33– 38), the total lamellae on one hand (48 versus 38–47), the total strigae on ten scales (144 versus 228–231), the relative length of digits on one hindlimb (36.8 versus 24.3–30.9), the relative distance between angled subocular and mouth (0.533 versus 0.620 –0.725), the relative forelimb length (23.5 versus 18.5–20.6), the relative ear width (1.60 versus 0.929–1.58), the relative rostral height (2.23 versus 1.86–2.06), the relative mental width (1.73 versus 1.92– 1.94), the relative cloacal width (7.61 versus 8.55–8.81), the relative prefrontal width (4.69 versus 4.73–4.75), the relative largest supraocular width (3.12 versus 1.91–2.77), the relative longest finger length (6.65 versus 4.49–4.55), the relative distance between the ear and eye (7.61 versus 7.78–8.43), the relative head width (70.8 versus 77.7– 78.1), the relative frontal width (58.2 versus 77.6–79.0), the relative nasal height (1.15 versus 1.06–1.09), the relative angled subocular height (0.814 versus 0.838 –0.978), the relative distance between the eye and naris (5.52 versus 5.21), the relative angled subocular width (2.90 versus 2.71), and the relative nasal width (2.00 versus 1.81). From P. leionotus , we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 86.3–105), the total strigae on ten scales (144 versus 191–266), the relative length of digits on one hindlimb (36.8 versus 25.4–34.1), the relative cloacal width (7.61 versus 8.03–8.69), the relative largest supraocular width (3.12 versus 1.94–2.50), the relative longest finger length (6.65 versus 4.58–6.10), and the relative frontal width (58.2 versus 68.7–81.2). From P. marcanoi , we distinguish P. unicolor sp. nov. by the dorsal pattern (absent versus irregular dots/dots in chevrons), the head markings (absent versus present), the total lamellae on one hand (48 versus 36–44), the relative length of digits on one hindlimb (36.8 versus 26.3–31.9), the relative mental width (1.73 versus 1.75–2.33), the relative frontal width (58.2 versus 59.0–73.0), the relative angled subocular height (0.814 versus 0.505 –0.793), and the relative nasal width (2.00 versus 1.64–1.96). From P. melanchrous , we distinguish P. unicolor sp. nov. by the adult SVL (67.6 versus 93.2–124), the total strigae on ten scales (144 versus 168–413), the relative frontal width (58.2 versus 61.3–71.4), the relative nasal height (1.15 versus 0.897 –0.952), and the relative angled subocular width (2.90 versus 2.28–2.82). From P. neiba , we distinguish P. unicolor sp. nov. by the dorsal pattern (absent versus irregular flecks/dots in chevrons), the adult SVL (67.6 versus 77.9–102), the total strigae on ten scales (144 versus 179–239), the relative length of digits on one hindlimb (36.8 versus 29.5–36.6), the relative distance between angled subocular and mouth (0.533 versus 0.670 –0.747), the relative largest supraocular width (3.12 versus 2.06–3.04), the relative frontal width (58.2 versus 63.3–74.0), the relative nasal height (1.15 versus 0.963–1.08), the relative distance between the eye and naris (5.52 versus 4.51–5.01), the relative angled subocular width (2.90 versus 2.34–2.83), and the relative nasal width (2.00 versus 1.67–1.92). From P. nesobous , we distinguish P. unicolor sp. nov. by the dorsal pattern (absent versus irregular dots/dots in series) and the total lamellae on one hand (48 versus 50–59). From P. oreistes , we distinguish P. unicolor sp. nov. by the dorsal pattern (absent versus irregular dots/dots in series/dots in chevrons), the adult SVL (67.6 versus 77.3–103), the total strigae on ten scales (144 versus 155–267), the relative frontal width (58.2 versus 61.6–76.9), the relative nasal height (1.15 versus 0.878–1.06), and the relative nasal width (2.00 versus 1.37–1.65). From P. psychonothes , we distinguish P. unicolor sp. nov. by the dorsal pattern (absent versus irregular dots/dots in series/dots in chevrons), the adult SVL (67.6 versus 70.9–97.2), the total lamellae on one hand (48 versus 37–44), the total strigae on ten scales (144 versus 172–244), the relative length of digits on one hindlimb (36.8 versus 26.5–33.1), the relative largest supraocular width (3.12 versus 1.92–2.68), the relative longest finger length (6.65 versus 4.89–5.81), the relative frontal width (58.2 versus 66.5–81.0), the relative angled subocular width (2.90 versus 2.01–2.44), and the relative nasal width (2.00 versus 1.68–1.94). From P. saonae , we distinguish P. unicolor sp. nov. by the longitudinal paramedian lines (present versus absent), the adult SVL (67.6 versus 90.9– 98.3), the midbody scale rows (40 versus 35–39), the total strigae on ten scales (144 versus 212–284), the relative eye length (3.38 versus 3.06–3.20), the relative ear width (1.60 versus 0.880–1.35), and the relative head length (17.8 versus 15.4–17.5). From P. semitaeniatus sp. nov., we distinguish P. unicolor sp. nov. by the SVL (67.6 versus 77.4–84.1), the total lamellae on one hand (48 versus 34–46), the total strigae on ten scales (144 versus 174–204), the relative length of digits on one hindlimb (36.8 versus 30.4–34.6), the relative distance between angled subocular and mouth (0.533 versus 0.666 –0.808), the relative ear width (1.6 versus 1.90–2.30), the relative cloacal width (7.61 versus 8.08–8.23), the relative longest finger length (6.65 versus 5.17–6.05), the relative head width (70.8 versus 58.8–63.8), and the relative frontal width (58.2 versus 63.6–76.5).

Description of holotype. ANSP 38647. An adult; SVL 67.6 mm; tail nearly cylindrical, broken in life midway, regenerated, 55.6 mm (82.2% SVL); axilla-to-groin distance 37.9 mm (56.1% SVL); forelimb length 15.8 mm (23.4% SVL); hindlimb length 22.7 mm (33.6% SVL); head length 12.0 mm (17.8% SVL); head width 8.50 mm (12.6% SVL); head width 70.8% head length; diameter of orbit 2.28 mm (3.37% SVL); horizontal diameter of ear opening 1.08 mm (1.60% SVL); vertical diameter of ear opening 0.88 mm (1.30% SVL); length of all toes on one foot 24.9 mm (36.8% SVL); shortest distance between angled subocular and lip 0.36 mm (0.533% SVL); shortest distance between the ocular and auricular openings 5.14 mm (7.60% SVL); longest finger length 4.49 mm (6.64% SVL); largest supraocular width 2.11 mm (3.12% SVL); cloacal width 5.14 mm (7.60% SVL); mental width 1.17 mm (1.73% SVL); postmental width 1.89 mm (2.80% SVL); prefrontal width 3.17 mm (4.69% SVL); frontal width 58.2% frontal length; nasal height 0.78 mm (1.15% SVL); angled subocular height 0.55 mm (0.814% SVL); shortest distance between the eye and naris 3.73 mm (5.52% SVL); canthal iii width 1.21 mm (1.79% SVL); angled subocular width 1.96 mm (2.90% SVL); nasal width 1.35 mm (2.00% SVL); rostral 2.23X 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, 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 smaller than parietals and separating them, posteriorly touching the interoccipital, which is 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); 2 suboculars (left)/(right); posterior subocular large and elongate (left)/(right); anterior subocular small; 9 supralabials (left)/(right), 6 to level below center of eye (left)/(right); 10 (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, followed by 1 pair of reduced chin shields; 1 st pair in contact with one another; 2 nd –5 th pairs separated by 1–5 scales; 96 transverse rows of dorsal scales from interoccipital to base of tail; 93 transverse rows of ventral scales from mental to vent; 40 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 12 lamellae under longest finger (left)/(right); 48 total lamellae on one hand; toe lengths 4>3>2>5>1; 16 (left)/17 (right) lamellae under longest toe; dorsal body and caudal scales keelless and striate; striate ventral scales; 144 total strigae counted on ten scales.

Color (in alcohol): dorsal surface of head medium gray, patternless; lateral surfaces of head grading from medium gray to cream with darker brown eye masks and markings on the labial scales; dorsal surfaces of the body are the same medium gray as the head with several dark brown flecks in the longitudinal paramedian area; dorsal surface of tail the same as the body except on the regenerated section, which is yellow; lateral areas grade from medium gray to cream with dark and pale dots arranged in bars in the lateral band; dorsal surfaces of the limbs are pale brown with darker brown mottling; lateral and ventral areas of the limbs grade to patternless cream; ventral surfaces of the head, body, and tail are patternless cream with several darker brown flecks under the chin.

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

Distribution. The only representative of Panolopus unicolor sp. nov. was collected near Cruce de Ocoa in the southcentral region of the Dominican Republic at 680 m (Fig. 49).

Ecology and conservation. Upon collection, the ravine in which the specimen was collected had “lots of native vegetation” and “even some very tall trees.”

We consider the conservation status of Panolopus unicolor to be Least Concern, based on IUCN Redlist criteria ( IUCN 2023). It is likely a common species tolerant of some habitat disturbance, based on what is known of most species of Panolopus . However, it is known from only a single specimen, and it faces a primary threat of habitat destruction resulting from deforestation. A secondary threat is predation from introduced mammals, including the mongoose and black rats. Studies are needed to determine the health and extent of remaining populations and better understand the threats to the survival of the species.

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

Etymology. The species name ( unicolor ) is a nominative singular masculine adjective, referring to the absence of a pattern on the dorsum of the holotype and only known specimen of this species.

Remarks. Only one individual of this species has ever been collected. No museum collection has specimens categorized as either P. curtissi or P. costatus from the nearby region, prompting the need for additional field surveys of the surrounding area to confirm the continued existence of this species. Panolopus unicolor sp. nov. is included in our genetic dataset and has significant support in both Bayesian and ML analyses at the stem node that places it as the closest relative to P. hylonomus . Based on our timetree (Fig. 4), P. unicolor sp. nov. diverged from its closest relative 0.85 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). We recognize P. unicolor sp. nov. as a distinct species because of the multiple morphological traits that separate it from P. hylonomus . Panolopus unicolor was recognized as a distinct species by our ASAP analysis.

Genus Sauresia Gray, 1852

Long-headed Four-toed Forest Lizards

(Fig. 80)

Sauresia Gray, 1852:282 . Type species: Sauresia sepsoides Gray, 1852:282 , by original designation.

Embryopus Weinland, 1863:135 . Type species: Embryopus habichii Weinland, 1863:135 , by original designation.

Diagnosis. Species of Sauresia have (1) a dorsal pattern of absent/irregular flecks/irregular dots/lineate/mottled, (2) head markings absent/present, (3) markings in the longitudinal paramedian area absent/present, (4) dots arranged in bars in the lateral band absent, (5) an adult SVL of 49.3–72.0 mm, (6) ventral scale rows, 101–129, (7) midbody scale rows, 31–42, (8) total lamellae on one hand, 14–19, (9) total strigae on ten scales, 78–150, (10) relative length of all digits on one hindlimb, 10.5–15.1 %, (11) relative distance between the angled subocular and mouth, 0.00–0.473 %, (12) relative eye length, 2.14–3.40 %, (13) relative forelimb length, 9.14–13.6 %, (14) relative ear width, 0.294–1.17 %, (15) relative rostral height, 1.45–2.73 %, (16) relative head length, 12.3–16.3 %, (17) relative mental width, 1.21–2.05 %, (18) relative postmental width, 1.92–2.76 %, (19) relative cloacal width, 5.11–7.18 %, (20) relative prefrontal width, 3.01–4.29 %, (21) relative largest supraocular width, 1.57–2.63 %, (22) relative longest finger length, 1.69–2.86 %, (23) relative distance between the ear and eye, 5.91–8.03 %, (24) relative head width, 64.7–83.1 %, (25) relative frontal width, 69.1–94.4 %, (26) relative nasal height, 0.706–1.17 %, (27) relative angled subocular height, 0.778–1.64 %, (28) relative distance between the eye and naris, 2.67–3.77 %, (29) relative canthal iii length, 0.943–1.82 %, (30) relative angled subocular width, 1.54–2.55 %, and (31) relative nasal length, 0.942–1.62 %. Notably, Sauresia possesses four digits (as opposed to five), a trait also observed in Wetmorena .

FIGURE 80. Map showing the distribution of Sauresia . Hollow symbols indicate unexamined records assignable to species. Small black dots indicate unexamined museum records not assignable to species.

Content. Eight species (Table 3): Sauresia agramma sp. nov., Sauresia cayemitae sp. nov., Sauresia gracilis sp. nov., Sauresia habichi , Sauresia manicula sp. nov., Sauresia pangnolae sp. nov., Sauresia sepsoides , and Sauresia synoria sp. nov.

Distribution: Sauresia is only known from Hispaniola but is notably absent from the driest parts of the island, including northwestern Haiti and some areas in the southern Dominican Republic.