Panolopus neiba ( Schwartz 1964 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 191-195

Panolopus neiba ( Schwartz 1964)

Dark Neiba Forest Lizard

(Fig. 70)

Diploglossus costatus neiba Schwartz, 1964:30 . Holotype: MCZ R-77155, collected by Richard Thomas from 19 km SW Hondo Valle , Elías Piña province, Dominican Republic, on 11 August 1963 (18.682, -71.788; 1,891 m).

Celestus costatus neiba — Schwartz & Henderson, 1988:95.

Celestus costatus neiba — Schwartz & Henderson, 1991:367.

Celestus costatus neiba — Hedges et al., 2019:16.

Celestus costatus neiba — Schools & Hedges, 2021:230.

Material examined (n=27). DOMINICAN REPUBLIC. San Rafael. Hispaniola . AMNH 92797 , Richard Thomas, 15 km SW Elías Piña , 13 August 1963 ; MCZ R-77155, Richard Thomas, 19 km SW Hondo Valle , 11 August 1963 . Independencia. ANSP 38579 , S. Blair Hedges, Matthew Heinicke, Eladio Fernandez, Andreas Schubert, ca. 7 km W by road Los Pinos , 24 August 2005 ; KU 225353–4 , Sabana Real, 0.7 mi W, 17.7 mi N La Descubierta , 6 September 1971 ; KU 225356–8 , Sabana Real, 14 km N Los Pinos , 25 July 1975 ; USNM 328763 , S. Blair Hedges and Richard Thomas, 9 km N of Cacique Enriquillo , 3 July 1986 ; USNM 328764 , Richard Thomas and S. Blair Hedges, 7 km N of Cacique Enriquillo , 4 July 1986 ; USNM 328765 , Richard Thomas and S. Blair Hedges, 6.2 km N, 4.0 km W (airline) of La Descubierta , 29 August 1984 . Elías Piña. KU 79826 , 15 km S Comendador , 17 August 1963 ; KU 225030–1 , 14 km SW Hondo Valle , 11 August 1963 ; USNM 328745–8 , S. Blair Hedges and Richard Thomas, ca. 24 km N of Los Pinos , 29 August 1984 ; USNM 328749–51 , S. Blair Hedges and Richard Thomas, ca. 27 km N of Los Pinos , 29 August 1984 ; USNM 328754–6 , Richard Thomas S. Blair Hedges, and locals, 17 km N of Cacique Enriquillo , 3 July 1986 ; USNM 328759 , S. Blair Hedges and Richard Thomas, 13 km N of Cacique Enriquillo , 2 July 1986 . Baoruco. MCZ R-171776–7, G. Flores and locals, Alto de la Pena, stream just off the path from El Aguacate (La Venta) to Sabana del Silencio , 17 July 1985 .

Diagnosis. Panolopus neiba has (1) a dorsal pattern of irregular flecks/dots in chevrons, (2) head markings absent, (3) markings in the longitudinal paramedian area absent/present, (4) dots arranged in bars in the lateral band present, (5) an adult SVL of 77.9–102 mm, (6) ventral scale rows, 84–102, (7) midbody scale rows, 35–43, (8) total lamellae on one hand, 45–49, (9) total strigae on ten scales, 179–239, (10) relative length of all digits on one hindlimb, 29.5–36.6 %, (11) relative distance between the angled subocular and mouth, 0.670 –0.747 %, (12) relative eye length, 2.95–3.93 %, (13) relative forelimb length, 19.8–25.7 %, (14) relative ear width, 0.966–1.97 %, (15) relative rostral height, 1.75–2.23 %, (16) relative head length, 15.4–19.8 %, (17) relative mental width, 1.66–2.36 %, (18) relative postmental width, 2.27–3.29 %, (19) relative cloacal width, 7.58–8.77 %, (20) relative prefrontal width, 4.41–5.49 %, (21) relative largest supraocular width, 2.06–3.04 %, (22) relative longest finger length, 5.61– 6.66 %, (23) relative distance between the ear and eye, 6.69–8.66 %, (24) relative head width, 67.9–78.4 %, (25) relative frontal width, 63.3–74.0 %, (26) relative nasal height, 0.963–1.08 %, (27) relative angled subocular height, 0.713 –0.885 %, (28) relative distance between the eye and naris, 4.51–5.01 %, (29) relative canthal iii length, 1.51–1.95 %, (30) relative angled subocular width, 2.34–2.83 %, and (31) relative nasal length, 1.67–1.92 %. The species stem time is 1.23 Ma and the species crown time is 0.40 Ma (Fig. 4).

FIGURE 70. (A–F) Panolopus neiba (MCZ R-77155, holotype), SVL 88.4 mm.

We distinguish Panolopus neiba from the other species of Panolopus based on a complex of traits. From P. aenetergum , we distinguish P. neiba by the dorsal pattern (irregular flecks/dots in chevrons versus irregular dots), the total lamellae on one hand (45–49 versus 40), the total strigae on ten scales (179–239 versus 267), the relative length of digits on one hindlimb (29.5–36.6 versus 26.8), the relative mental width (1.66–2.36 versus 1.63), the relative prefrontal width (4.41–5.49 versus 4.15), the relative longest finger length (5.61–6.66 versus 4.83), the relative frontal width (63.3–74.0 versus 88.2), the relative nasal height (0.963–1.08 versus 1.15), the relative angled subocular height (0.713 –0.885 versus 1.08), the relative distance between the eye and naris (4.51–5.01 versus 4.35), and the relative angled subocular width (2.34–2.83 versus 2.07). From P. aporus , we distinguish P. neiba by the relative distance between angled subocular and mouth (0.670 –0.747 versus 0.441 –0.669). From P. chalcorhabdus , we distinguish P. neiba by the relative width of canthal iii (1.51–1.95 versus 1.98–2.05). From P. costatus , we distinguish P. neiba by the relative distance between the eye and naris (4.51–5.01 versus 5.08–5.50). From P. curtissi , we distinguish P. neiba by the dots arranged in bars in the lateral areas (present versus absent), the total lamellae on one hand (45–49 versus 32–39), the relative length of digits on one hindlimb (29.5–36.6 versus 20.8– 28.1), the relative distance between angled subocular and mouth (0.670 –0.747 versus 0.393 –0.587), and the relative longest finger length (5.61–6.66 versus 3.59–4.54). From P. diastatus , we distinguish P. neiba by the total lamellae on one hand (45–49 versus 35–41), the relative length of digits on one hindlimb (29.5–36.6 versus 21.5–27.4), the relative distance between angled subocular and mouth (0.670 –0.747 versus 0.00–0.614), and the relative longest finger length (5.61–6.66 versus 3.48–4.87). From P. emys , we distinguish P. neiba by the relative prefrontal width (4.41–5.49 versus 3.99–4.36), the relative angled subocular width (2.34–2.83 versus 2.12–2.20), and the relative nasal width (1.67–1.92 versus 1.23–1.58). From P. hylonomus , we distinguish P. neiba by the dots arranged in bars in the lateral areas (present versus absent), the adult SVL (77.9–102 versus 59.3–76.5), the relative length of digits on one hindlimb (29.5–36.6 versus 22.8–28.2), and the relative longest finger length (5.61–6.66 versus 4.47–5.27). From P. lanceolatus sp. nov., we distinguish P. neiba by the frontal width by the SVL (3.86–4.52 versus 3.48–3.84) (see Remarks). From P. lapierrae sp. nov., we distinguish P. neiba by the relative longest finger length (5.61–6.66 versus 4.49–4.55), the relative frontal width (63.3–74.0 versus 77.6–79.0), and the relative distance between the eye and naris (4.51–5.01 versus 5.21). From P. leionotus , we distinguish P. neiba by the nasal height by the nasal width (1.82–2.18 versus 1.47–1.80) (see Remarks). From P. marcanoi , we distinguish P. neiba by the head markings (absent versus present) and the total lamellae on one hand (45–49 versus 36–44). From P. melanchrous , we distinguish P. neiba by the relative nasal height (0.963–1.08 versus 0.897 –0.952). From P. nesobous , we distinguish P. neiba by the dorsal pattern (irregular flecks/dots in chevrons versus irregular dots/dots in series), the total lamellae on one hand (45–49 versus 50–59), the relative rostral height (1.75–2.23 versus 2.26–2.38), the relative nasal height (0.963–1.08 versus 1.12–1.14), the relative distance between the eye and naris (4.51–5.01 versus 5.62–5.73), and the relative width of canthal iii (1.51–1.95 versus 2.01–2.12). From P. oreistes , we distinguish P. neiba by the relative nasal width (1.67–1.92 versus 1.37–1.65). From P. psychonothes , we distinguish P. neiba by the total lamellae on one hand (45–49 versus 37–44) and the relative nasal height (0.963–1.08 versus 1.12–1.32). From P. saonae , we distinguish P. neiba by the dorsal pattern (irregular flecks/dots in chevrons versus absent), the total lamellae on one hand (45–49 versus 40–42), the relative distance between angled subocular and mouth (0.670 –0.747 versus 0.517 –0.630), the relative mental width (1.66–2.36 versus 1.52), the relative prefrontal width (4.41–5.49 versus 4.14), the relative longest finger length (5.61–6.66 versus 5.01), the relative distance between the eye and naris (4.51–5.01 versus 6.43), the relative width of canthal iii (1.51–1.95 versus 1.99), and the relative angled subocular width (2.34–2.83 versus 2.31). From P. semitaeniatus sp. nov., we distinguish P. neiba by the relative rostral height (1.75–2.23 versus 2.41–2.63), the relative head width (67.9–78.4 versus 58.8–63.8), the relative angled subocular height (0.713 –0.885 versus 0.654), and the relative nasal width (1.67–1.92 versus 1.51). From P. unicolor sp. nov., we distinguish P. neiba by the dorsal pattern (irregular flecks/dots in chevrons versus absent), the adult SVL (77.9–102 versus 67.6), the total strigae on ten scales (179–239 versus 144), the relative length of digits on one hindlimb (29.5–36.6 versus 36.8), the relative distance between angled subocular and mouth (0.670 –0.747 versus 0.533), the relative largest supraocular width (2.06–3.04 versus 3.12), the relative frontal width (63.3–74.0 versus 58.2), the relative nasal height (0.963–1.08 versus 1.15), the relative distance between the eye and naris (4.51–5.01 versus 5.52), the relative angled subocular width (2.34–2.83 versus 2.90), and the relative nasal width (1.67–1.92 versus 2.00).

Description of holotype. MCZ R-77155. An adult female; SVL 88.4 mm; tail nearly cylindrical, broken in life midway, regenerated, 58.5 mm (66.2% SVL); axilla-to-groin distance 51.3 mm (58.0% SVL); forelimb length 19.9 mm (22.5% SVL); hindlimb length 28.6 mm (32.4% SVL); head length 15.6 mm (17.6% SVL); head width 10.6 mm (12.0% SVL); head width 67.9% head length; diameter of orbit 2.99 mm (3.38% SVL); horizontal diameter of ear opening 1.39 mm (1.57% SVL); vertical diameter of ear opening 1.52 mm (1.72% SVL); length of all toes on one foot 27.8 mm (31.4% SVL); shortest distance between angled subocular and lip 0.60 mm (0.679% SVL); shortest distance between the ocular and auricular openings 7.08 mm (8.01% SVL); longest finger length 5.80 mm (6.56% SVL); largest supraocular width 1.82 mm (2.06% SVL); cloacal width 7.75 mm (8.77% SVL); mental width 1.68 mm (1.90% SVL); postmental width 2.41 mm (2.73% SVL); prefrontal width 3.90 mm (4.41% SVL); frontal width 63.3% frontal length; nasal height 0.92 mm (1.04% SVL); angled subocular height 0.63 mm (0.713% SVL); shortest distance between the eye and naris 3.99 mm (4.51% SVL); canthal iii width 1.65 mm (1.87% SVL); angled subocular width 2.22 mm (2.51% SVL); nasal width 1.48 mm (1.67% SVL); rostral 1.95X 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, 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 slightly smaller than parietals and separating them, posteriorly touching the interoccipital, which is wider than long; parietal separated from supraoculars by 1 st temporals and frontoparietal (left)/1 st and 2 nd temporals and frontoparietal (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, median ocular 1, 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 preocular, 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 (left)/(right); 10 supralabials (left)/(right), 6 to level below center of eye (left)/(right); 10 (left)/11 (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 1–3 scales; 97 transverse rows of dorsal scales from interoccipital to base of tail; 90 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); 47 total lamellae on one hand; toe lengths 4>3>5>2>1; 17 lamellae under longest toe (left)/(right); keelless and striate dorsal body and caudal scales; smooth ventral scales; 190 total strigae counted on ten scales.

Color (in alcohol): dorsal surface of head medium brown, patternless; lateral surfaces of head grading from medium brown to cream with darker brown eye masks and other darker brown areas on the labial scales and sides of neck; dorsal surfaces of the body are red-gray with darker brown markings in longitudinal paramedian series and some darker brown irregular flecks on the remainder of the dorsum; dorsal surface of tail same as body, dark yellow on the regenerated section; lateral areas lateral areas grade from dark red-brown to cream with darker brown dots arranged in bars; dorsal surfaces of the limbs are medium brown with darker brown mottling; lateral and ventral areas of the limbs fade to cream with less mottling; ventral surfaces of the head, body, and tail are cream with some pale brown spotting under the throat.

Variation. The dorsal pattern of the majority of the examined material resembles the holotype of irregularly occurring dots of flecks. At times, this pattern is arranged into chevrons. KU 79826 has dots only on the back of its neck. All specimens have patternless heads except for KU 225030 , which has some irregular flecks on its head scales. The holotype has the most pronounced longitudinal paramedian lines of the examined material with other specimens displaying broken longitudinal paramedian lines, dots in series, streaking, or even no markings ( MCZ R-171777). All examined material shows 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 neiba is distributed in the Sierra de Neiba of the Dominican Republic at elevations of 390–1920 m (Fig. 50).

Ecology and conservation. Little information is available on the ecology of this species other than that many specimens were collected under rocks.

We consider the conservation status of Panolopus neiba 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. A litter size of 4–8 (3.2–5.0 g) has been recorded in this species (SBH, field data).

Etymology. The species name ( neiba ) refers to the geographic distribution of this species in the Sierra de Neiba.

Remarks. Previously considered a subspecies of Panolopus costatus , herein we recognize P. neiba as a full species based on genetic and morphological differences. Additional museum specimens classified as P. costatus from the range of P. neiba should be examined to determine if they are members of this species.

Panolopus neiba and P. lanceolatus sp. nov. cannot be morphologically separated based on our standard suite of characters, however, they can be separated by the frontal width divided by the SVL (3.86–4.52 [n=5] versus 3.48–3.84 [n=8]). Panolopus neiba and P. leionotus cannot be morphologically separated based on our standard suite of characters; however, they can be separated by the nasal height by the nasal width (1.82–2.18 [n=5] versus 1.47–1.80 [n=7]).

Panolopus neiba is included in our genetic dataset and has significant support in ML and Bayesian analyses at the crown node and the stem node that places it outside of P. leionotus and P. semitaeniatus sp. nov. Based on our timetree (Fig. 4), P. neiba diverged from its closest relative 1.23 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). We further recognize P. neiba as a distinct species because of the diagnostic traits that separate it from both P. leionotus and P. semitaeniatus sp. nov. Panolopus neiba also occurs in sympatry with P. leionotus . Panolopus neiba was recovered as conspecific with Panolopus leionotus and Panolopus semitaeniatus sp. nov. in our ASAP analysis.