Panolopus diastatus ( Schwartz 1964 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 157-161

Panolopus diastatus ( Schwartz 1964)

Northwestern Smooth-scaled Forest Lizard

(Fig. 59)

Diploglossus curtissi diastatus Schwartz, 1964:42 . Holotype: MCZ R-63402, collected by Austin Stanley Rand and James Draper Lazell, Jr. from Bombardopolis, Nord-Ouest department, Haiti, on 22 July 1960 (19.695, -73.341).

Celestus curtissi diastatus — Schwartz & Henderson, 1988:98.

Celestus curtissi diastatus — Schwartz & Henderson, 1991:371.

Celestus curtissi diastatus — Hedges et al., 2019:17.

Material examined (n=16). HAITI. AMNH 49816 , William G. Hassler, N part of Haiti, near intersection of Jean Rabel and Port a l’Ecu Road, 2 April 1935 . Nord’Ouest. ANSP 38636–40 , S. Blair Hedges and Richard Thomas , Bombardopolis, 28 April 1997 ; ANSP 38641–2 , S. Blair Hedges and Richard Thomas, about 3.5 mi SW Bombardopolis (on S facing slope of Morne Tony ), 29 April 1997 ; ANSP 38643–6 , S. Blair Hedges, Richard Thomas, and Felix Charles , Mole St. Nicolas, 25 April 1997 . Port-de-Paix. MCZ R-63395, R-63400, R-63402, Austin Stanley Rand, James Draper Lazell , Jr., Bombardopolis, 22 July 1960 ; MCZ R-63412, Austin Stanley Rand, James Draper Lazell, Jr. , Mole St. Nicolas, 26 July 1960 .

Diagnosis. Panolopus diastatus has (1) a dorsal pattern of absent/irregular flecks, (2) head markings absent, (3) markings in the longitudinal paramedian area absent, (4) dots arranged in bars in the lateral band absent/present, (5) an adult SVL of 66.1–83.7 mm, (6) ventral scale rows, 86–114, (7) midbody scale rows, 33–39, (8) total lamellae on one hand, 35–41, (9) total strigae on ten scales, 169–234, (10) relative length of all digits on one hindlimb, 21.5– 27.4 %, (11) relative distance between the angled subocular and mouth, 0.00–0.614 %, (12) relative eye length, 2.71–3.32 %, (13) relative forelimb length, 16.2–20.1 %, (14) relative ear width, 0.667–1.43 %, (15) relative rostral height, 1.89–2.45 %, (16) relative head length, 14.2–18.8 %, (17) relative mental width, 1.51–2.00 %, (18) relative postmental width, 2.43–3.17 %, (19) relative cloacal width, 7.15–8.06 %, (20) relative prefrontal width, 3.74–4.61 %, (21) relative largest supraocular width, 1.88–2.57 %, (22) relative longest finger length, 3.48–4.87 %, (23) relative distance between the ear and eye, 6.32–8.58 %, (24) relative head width, 69.4–74.8 %, (25) relative frontal width, 57.4–86.2 %, (26) relative nasal height, 0.913–1.19 %, (27) relative angled subocular height, 0.564–1.08 %, (28) relative distance between the eye and naris, 4.06–4.94 %, (29) relative canthal iii length, 1.21–2.70 %, (30) relative angled subocular width, 1.93–2.86 %, and (31) relative nasal length, 1.41–1.77 %. The species stem time is 1.81 Ma and the species crown time is 0.23 Ma (Fig. 4).

FIGURE 59. (A–F) Panolopus diastatus (MCZ R-63402, holotype), SVL 83.7 mm.

We distinguish Panolopus diastatus from the other species of Panolopus based on a complex of traits. From Panolopus aenetergum , we distinguish P. diastatus by the dorsal pattern (absent/irregular flecks versus irregular dots), the total strigae on ten scales (169–234 versus 267), the relative distance between angled subocular and mouth (0.00–0.614 versus 0.717), the relative eye length (2.71–3.32 versus 3.34), the relative forelimb length (16.2–20.1 versus 20.6), the relative head width (69.4–74.8 versus 76.4), the relative frontal width (57.4–86.2 versus 88.2), and the relative nasal width (1.41–1.77 versus 1.92). From P. aporus , we distinguish P. diastatus by the relative length of digits on one hindlimb (21.5–27.4 versus 27.7–33.7) and the relative largest supraocular width (1.88–2.57 versus 2.74–3.62). From P. chalcorhabdus , we distinguish P. diastatus by the relative length of digits on one hindlimb (21.5–27.4 versus 31.3–36.0), the relative forelimb length (16.2–20.1 versus 20.4–23.7), and the relative longest finger length (3.48–4.87 versus 5.29–6.97). From P. costatus , we distinguish P. diastatus by the total lamellae on one hand (35–41 versus 49–58), the relative length of digits on one hindlimb (21.5–27.4 versus 31.5–37.8), the relative longest finger length (3.48–4.87 versus 5.53–6.66), and the relative distance between the eye and naris (4.06–4.94 versus 5.08–5.50). From P. curtissi , we distinguish P. diastatus by the nasal height by the nasal length by the nasal height (1.47–1.73 versus 1.21–1.46) (see Remarks). From P. emys , we distinguish P. diastatus by the adult SVL (66.1–83.7 versus 99.0–113), the total strigae on ten scales (169–234 versus 238–311), the relative length of digits on one hindlimb (21.5–27.4 versus 28.9–35.2), the relative cloacal width (7.15–8.06 versus 8.24–8.96), and the relative longest finger length (3.48–4.87 versus 5.15–5.83). From P. hylonomus , we distinguish P. diastatus by the relative largest supraocular width (1.88–2.57 versus 2.65–2.90). From P. lanceolatus sp. nov., we distinguish P. diastatus by the longitudinal paramedian lines (absent versus present) and the relative length of digits on one hindlimb (21.5–27.4 versus 28.4–35.9). From P. lapierrae sp. nov., we distinguish P. diastatus by the relative distance between angled subocular and mouth (0.00–0.614 versus 0.620 –0.725), the relative cloacal width (7.15–8.06 versus 8.55–8.81), the relative prefrontal width (3.74–4.61 versus 4.73–4.75), the relative head width (69.4–74.8 versus 77.7–78.1), the relative distance between the eye and naris (4.06–4.94 versus 5.21), and the relative nasal width (1.41–1.77 versus 1.81). From P. leionotus , we distinguish P. diastatus by the adult SVL (66.1–83.7 versus 86.3–105) and the total lamellae on one hand (35–41 versus 43–48). From P. marcanoi , we distinguish P. diastatus by the dorsal pattern (absent/irregular flecks versus irregular dots/dots in chevrons), the head markings (absent versus present), and the longitudinal paramedian lines (absent versus present). From P. melanchrous , we distinguish P. diastatus by the longitudinal paramedian lines (absent versus present), the adult SVL (66.1–83.7 versus 93.2–124), the total lamellae on one hand (35–41 versus 47–58), the relative length of digits on one hindlimb (21.5–27.4 versus 30.7–41.3), and the relative longest finger length (3.48–4.87 versus 5.76–7.09). From P. neiba , we distinguish P. diastatus by the total lamellae on one hand (35–41 versus 45–49), the relative length of digits on one hindlimb (21.5–27.4 versus 29.5–36.6), the relative distance between angled subocular and mouth (0.00–0.614 versus 0.670 –0.747), and the relative longest finger length (3.48–4.87 versus 5.61–6.66). From P. nesobous , we distinguish P. diastatus by the dorsal pattern (absent/irregular flecks versus irregular dots/dots in series), the longitudinal paramedian lines (absent versus present), the total lamellae on one hand (35–41 versus 50–59), the relative length of digits on one hindlimb (21.5–27.4 versus 35.1), the relative eye length (2.71–3.32 versus 3.41–3.63), the relative forelimb length (16.2–20.1 versus 23.3–25.1), the relative cloacal width (7.15–8.06 versus 8.11–8.21), the relative prefrontal width (3.74–4.61 versus 4.74–4.81), the relative largest supraocular width (1.88–2.57 versus 2.85–3.11), the relative longest finger length (3.48–4.87 versus 6.19–6.33), and the relative distance between the eye and naris (4.06–4.94 versus 5.62–5.73). From P. oreistes , we distinguish P. diastatus by the dorsal pattern (absent/irregular flecks versus irregular dots/dots in series/dots in chevrons), the longitudinal paramedian lines (absent versus present), the relative length of digits on one hindlimb (21.5–27.4 versus 31.2–40.1), the relative longest finger length (3.48–4.87 versus 5.27–7.23), and the relative distance between the eye and naris (4.06–4.94 versus 5.01–5.63). From P. psychonothes , we distinguish P. diastatus by the dorsal pattern (absent/irregular flecks versus irregular dots/dots in series/dots in chevrons) and the relative longest finger length (3.48–4.87 versus 4.89–5.81). From P. saonae , we distinguish P. diastatus by the adult SVL (66.1–83.7 versus 90.9–98.3), the relative cloacal width (7.15–8.06 versus 8.20), the relative largest supraocular width (1.88–2.57 versus 2.77), the relative longest finger length (3.48–4.87 versus 5.01), and the relative distance between the eye and naris (4.06–4.94 versus 6.43). From P. semitaeniatus sp. nov., we distinguish P. diastatus by the relative length of digits on one hindlimb (21.5–27.4 versus 30.4–34.6), the relative distance between angled subocular and mouth (0.00–0.614 versus 0.666 –0.808), the relative forelimb length (16.2– 20.1 versus 21.3–23.8), the relative ear width (0.667–1.43 versus 1.90–2.30), the relative cloacal width (7.15–8.06 versus 8.08–8.23), the relative largest supraocular width (1.88–2.57 versus 2.59–3.32), the relative longest finger length (3.48–4.87 versus 5.17–6.05), and the relative head width (69.4–74.8 versus 58.8–63.8). From P. unicolor sp. nov., we distinguish P. diastatus by the longitudinal paramedian lines (absent versus present), the midbody scale rows (33–39 versus 40), the total lamellae on one hand (35–41 versus 48), the total strigae on ten scales (169–234 versus 144), the relative length of digits on one hindlimb (21.5–27.4 versus 36.8), the relative eye length (2.71–3.32 versus 3.38), the relative forelimb length (16.2–20.1 versus 23.5), the relative ear width (0.667–1.43 versus 1.60), the relative prefrontal width (3.74–4.61 versus 4.69), the relative largest supraocular width (1.88–2.57 versus 3.12), the relative longest finger length (3.48–4.87 versus 6.65), the relative distance between the eye and naris (4.06–4.94 versus 5.52), the relative angled subocular width (1.93–2.86 versus 2.90), and the relative nasal width (1.41–1.77 versus 2.00).

Description of holotype. MCZ R-63402. An adult male; SVL 83.7 mm; tail nearly cylindrical, broken in life midway, regenerated, 67.7 mm (80.9% SVL); axilla-to-groin distance 50.8 mm (60.7% SVL); forelimb length 16.7 mm (20.0% SVL); hindlimb length 21.8 mm (26.0% SVL); head length 14.7 mm (17.6% SVL); head width 10.7 mm (12.8% SVL); head width 72.8% head length; diameter of orbit 2.35 mm (2.81% SVL); horizontal diameter of ear opening 0.91 mm (1.09% SVL); vertical diameter of ear opening 1.25 mm (1.49% SVL); length of all toes on one foot 21.7 mm (25.9% SVL); shortest distance between angled subocular and lip 0.40 mm (0.478% SVL); shortest distance between the ocular and auricular openings 7.18 mm (8.58% SVL); longest finger length 3.69 mm (4.41% SVL); largest supraocular width 1.57 mm (1.88% SVL); cloacal width 6.68 mm (7.98% SVL); mental width 1.54 mm (1.84% SVL); postmental width 2.28 mm (2.72% SVL); prefrontal width 3.33 mm (3.98% SVL); frontal width 86.2% frontal length; nasal height 0.98 mm (1.17% SVL); angled subocular height 0.90 mm (1.08% SVL); shortest distance between the eye and naris 3.59 mm (4.29% SVL); canthal iii width 1.49 mm (1.78% SVL); angled subocular width 2.39 mm (2.86% SVL); nasal width 1.45 mm (1.73% SVL); rostral 1.89X 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, much wider than long also fused with frontal, 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)/upper and lower preoculars (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)/1 st median ocular, anterior supraciliary, upper preocular, and 1 st and 2 nd loreals (right); 10 (left)/9 (right) median oculars, 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 (left)/(right); 9 supralabials (left)/(right), 6 to level below center of eye (left)/(right); 9 infralabials (left)/(right), 6 (left)/5 (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 –4 th pairs separated by 1–2 scales; 95 transverse rows of dorsal scales from interoccipital to base of tail; 86 transverse rows of ventral scales from mental to vent; 35 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 10 lamellae under longest finger (left)/(right); 39 total lamellae on one hand; toe lengths 4>3>5>2>1; 16 lamellae under longest toe (left)/(right); keelless and striate dorsal body and caudal scales; smooth ventral scales; 211 total strigae counted on ten scales.

Color (in alcohol): dorsal surface of head gray-brown, patternless; lateral surfaces of head grading from gray-brown to cream with darker brown eye masks and other darker brown areas on the supralabial scales; dorsal surfaces of the body are gray-brown with irregular darker brown spots towards the posterior; dorsal surface of tail red-gray to yellow (on regenerated section) with irregular darker brown spots; lateral areas fading from dark red-brown to yellow-cream with some irregular off-white dots; dorsal surfaces of the limbs are golden tan with darker brown mottling; lateral and ventral areas of the limbs fade to pale cream, patternless; ventral surfaces of the head, body, and tail are cream, patternless except for a few darker brown flecks under the chin.

Variation. The majority of examined specimens lack a dorsal pattern with a few specimens displaying several irregular flecks posteriorly. No specimens show a patterned head, longitudinal paramedian markings, or dots arranged in bars in the lateral band. Measurements and other morphological data for the holotype and other examined material are presented in Table 1.

Distribution. Panolopus diastatus is distributed in northwestern Haiti at elevations of 10–500 m (Fig. 49).

Ecology and conservation. No ecological data are available for this species. We consider the conservation status of Panolopus diastatus 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 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 name is from the Greek noun diastatus , meaning divided, in allusion to the large distributional hiatus between Panolopus diastatus and P. curtissi , discussed in the original description ( Schwartz 1964).

Remarks. Previously regarded as a subspecies of Panolopus curtissi , this species appears in multiple museum collections. Addition museum specimens catalogued as P. curtissi should be examined for diagnostic characters to potentially assign them to P. diastatus .

Panolopus diastatus and P. curtissi cannot be morphologically separated based on our standard suite of characters, however, they can be separated by the nasal length by the nasal height (1.21–1.46 [n=5] versus 1.47–1.73 [n=10]).

Panolopus diastatus was included in our genetic dataset and has significant support in both Bayesian and ML likelihood analyses at the crown node. The placement of P. diastatus within Panolopus had a support value of 63% in our ML analysis and was not supported in our Bayesian analysis. Schools et al. (2022) used genomic data to place P. diastatus outside of P. unicolor sp. nov., P. leionotus , P. marcanoi , P. neiba , and P. semitaeniatus sp. nov. with significant support in ML and Bayesian analyses. Based on our timetree (Fig. 4), P. diastatus diverged from its closest relative 1.81 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). Panolopus diastatus was recognized as a distinct species by our ASAP analysis.