Panolopus nesobous ( Schwartz 1964 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 195-200

Panolopus nesobous ( Schwartz 1964)

Ile-a-Vache Forest Lizard

(Fig. 71–72)

Diploglossus costatus nesobous Schwartz, 1964:23 . Holotype: MCZ R-77153, collected by Albert Schwartz, Jr. on Ile-a-Vache, Sud department, Haiti, on 6 August 1962 (18.10, -73.70).

Celestus costatus nesobous — Schwartz & Henderson, 1988:96.

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

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

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

Material examined (n=8). HAITI. Sud. ANSP 38580–2 , S. Blair Hedges, Richard Thomas, Nicholas Plummer, and Manuel Leal, Caye Michel, previously called Caye Paul (10.7 km WNW Les Platons Citadel), 1 June 1991 ; KU 225032–3 , Île-à-Vache western end, 6 August 1962 ; ANSP 38583 , locals, Île-à-Vache, 24 July 2011 ; MCZ R-77153, Albert Schwartz, Jr., Île-à-Vache, western end, 6 August 1962 ; SBH 269117 , Plaine Formon near Caye Michel .

Diagnosis. Panolopus nesobous has (1) a dorsal pattern of irregular dots/dots in series, (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 82.3–108 mm, (6) ventral scale rows, 77–96, (7) midbody scale rows, 38–43, (8) total lamellae on one hand, 50–59, (9) total strigae on ten scales, 155–222, (10) relative length of all digits on one hindlimb, 35.1 %, (11) relative distance between the angled subocular and mouth, 0.486 –0.843 %, (12) relative eye length, 3.41–3.63 %, (13) relative forelimb length, 23.3–25.1 %, (14) relative ear width, 1.39–1.60 %, (15) relative rostral height, 2.26–2.38 %, (16) relative head length, 17.9–19.8 %, (17) relative mental width, 1.96–2.18 %, (18) relative postmental width, 2.82–3.02 %, (19) relative cloacal width, 8.11–8.21 %, (20) relative prefrontal width, 4.74–4.81 %, (21) relative largest supraocular width, 2.85–3.11 %, (22) relative longest finger length, 6.19–6.33 %, (23) relative distance between the ear and eye, 7.91–10.0 %, (24) relative head width, 71.2–76.4 %, (25) relative frontal width, 60.8–63.5 %, (26) relative nasal height, 1.12–1.14 %, (27) relative angled subocular height, 0.669 – 0.750 %, (28) relative distance between the eye and naris, 5.62–5.73 %, (29) relative canthal iii length, 2.01–2.12 %, (30) relative angled subocular width, 2.61–2.82 %, and (31) relative nasal length, 1.69–1.71 %. The species stem time is 3.51 Ma and the species crown time is 0.02 Ma (Fig. 4).

We distinguish Panolopus nesobous from the other species of Panolopus based on a complex of traits. From Panolopus aenetergum , we distinguish P. nesobous by the longitudinal paramedian lines (present versus absent), the midbody scale rows (38–43 versus 35–36), and the total lamellae on one hand (50–59 versus 40). From P. aporus , we distinguish P. nesobous by the total lamellae on one hand (50–59 versus 36–48), the relative length of digits on one hindlimb (35.1 versus 27.7–33.7), the relative prefrontal width (4.74–4.81 versus 4.18–4.53), the relative longest finger length (6.19–6.33 versus 4.57–5.72), the relative distance between the eye and naris (5.62–5.73 versus 4.69– 5.44), and the relative width of canthal iii (2.01–2.12 versus 1.85–1.96). From P. chalcorhabdus , we distinguish P. nesobous by the relative rostral height (2.26–2.38 versus 1.85–2.24). From P. costatus , we distinguish P. nesobous by the relative prefrontal width (4.74–4.81 versus 3.97–4.67), the relative distance between the eye and naris (5.62– 5.73 versus 5.08–5.50), and the relative width of canthal iii (2.01–2.12 versus 1.82–1.90). From P. curtissi , we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus absent/irregular flecks), the dots arranged in bars in the lateral areas (present versus absent), the total lamellae on one hand (50–59 versus 32–39), the relative length of digits on one hindlimb (35.1 versus 20.8–28.1), the relative forelimb length (23.3–25.1 versus 15.1–20.5), the relative postmental width (2.82–3.02 versus 2.07–2.72), the relative prefrontal width (4.74–4.81 versus 3.96–4.68), the relative longest finger length (6.19–6.33 versus 3.59–4.54), the relative distance between the ear and eye (7.91–10.0 versus 5.36–7.71), the relative frontal width (60.8–63.5 versus 65.4–83.1), the relative distance between the eye and naris (5.62–5.73 versus 4.02–5.03), and the relative width of canthal iii (2.01–2.12 versus 1.75–1.93). From P. diastatus , we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus absent/irregular flecks), the longitudinal paramedian lines (present versus absent), the total lamellae on one hand (50–59 versus 35–41), the relative length of digits on one hindlimb (35.1 versus 21.5–27.4), the relative eye length (3.41–3.63 versus 2.71–3.32), the relative forelimb length (23.3–25.1 versus 16.2–20.1), the relative cloacal width (8.11–8.21 versus 7.15–8.06), the relative prefrontal width (4.74–4.81 versus 3.74–4.61), the relative largest supraocular width (2.85–3.11 versus 1.88–2.57), the relative longest finger length (6.19–6.33 versus 3.48–4.87), and the relative distance between the eye and naris (5.62–5.73 versus 4.06–4.94). From P. emys , we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus absent/irregular flecks), the total strigae on ten scales (155–222 versus 238–311), the relative eye length (3.41–3.63 versus 2.87–3.40), the relative cloacal width (8.11–8.21 versus 8.24–8.96), the relative prefrontal width (4.74–4.81 versus 3.99–4.36), the relative longest finger length (6.19–6.33 versus 5.15–5.83), the relative frontal width (60.8–63.5 versus 67.7–74.5), the relative nasal height (1.12–1.14 versus 0.963–1.10), the relative distance between the eye and naris (5.62–5.73 versus 4.37–5.19), the relative angled subocular width (2.61–2.82 versus 2.12–2.20), and the relative nasal width (1.69–1.71 versus 1.23–1.58). From P. hylonomus , we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus absent/irregular flecks), the dots arranged in bars in the lateral areas (present versus absent), the adult SVL (82.3– 108 versus 59.3–76.5), the total lamellae on one hand (50–59 versus 34–47), the relative length of digits on one hindlimb (35.1 versus 22.8–28.2), the relative forelimb length (23.3–25.1 versus 17.1–20.7), the relative longest finger length (6.19–6.33 versus 4.47–5.27), the relative frontal width (60.8–63.5 versus 64.0–74.5), and the relative distance between the eye and naris (5.62–5.73 versus 4.03–4.98). From P. lanceolatus sp. nov., we distinguish P. nesobous by the relative ear width (1.39–1.60 versus 0.770–1.35), the relative postmental width (2.82–3.02 versus 2.36–2.66), the relative prefrontal width (4.74–4.81 versus 3.97–4.55), the relative largest supraocular width (2.85– 3.11 versus 2.20–2.71), the relative distance between the ear and eye (7.91–10.0 versus 6.45–7.70), the relative nasal height (1.12–1.14 versus 0.904–1.06), the relative distance between the eye and naris (5.62–5.73 versus 4.58– 5.05), and the relative width of canthal iii (2.01–2.12 versus 1.73–2.00). From P. lapierrae sp. nov., we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus absent/dots in chevrons), the total lamellae on one hand (50–59 versus 38–47), the total strigae on ten scales (155–222 versus 228–231), the relative length of digits on one hindlimb (35.1 versus 24.3–30.9), the relative forelimb length (23.3–25.1 versus 18.5–20.6), the relative rostral height (2.26–2.38 versus 1.86–2.06), the relative mental width (1.96–2.18 versus 1.92–1.94), the relative cloacal width (8.11–8.21 versus 8.55–8.81), the relative largest supraocular width (2.85–3.11 versus 1.91– 2.77), the relative longest finger length (6.19–6.33 versus 4.49–4.55), the relative head width (71.2–76.4 versus 77.7–78.1), the relative frontal width (60.8–63.5 versus 77.6–79.0), the relative nasal height (1.12–1.14 versus 1.06–1.09), the relative angled subocular height (0.669 –0.750 versus 0.838 –0.978), and the relative width of canthal iii (2.01–2.12 versus 1.54–1.86). From P. leionotus , we distinguish P. nesobous by the total lamellae on one hand (50–59 versus 43–48), the relative length of digits on one hindlimb (35.1 versus 25.4–34.1), the relative largest supraocular width (2.85–3.11 versus 1.94–2.50), the relative longest finger length (6.19–6.33 versus 4.58–6.10), the relative frontal width (60.8–63.5 versus 68.7–81.2), the relative distance between the eye and naris (5.62–5.73 versus 4.46–5.61), and the relative width of canthal iii (2.01–2.12 versus 1.55–1.89). From P. marcanoi , we distinguish P. nesobous by the head markings (absent versus present), the total lamellae on one hand (50–59 versus 36–44), and the relative length of digits on one hindlimb (35.1 versus 26.3–31.9). From P. melanchrous , we distinguish P. nesobous by the relative nasal height (1.12–1.14 versus 0.897 –0.952), the relative distance between the eye and naris (5.62–5.73 versus 4.89–5.59), and the relative width of canthal iii (2.01–2.12 versus 1.67–1.94). From P. neiba , we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus irregular flecks/ dots in chevrons), the total lamellae on one hand (50–59 versus 45–49), the relative rostral height (2.26–2.38 versus 1.75–2.23), the relative nasal height (1.12–1.14 versus 0.963–1.08), the relative distance between the eye and naris (5.62–5.73 versus 4.51–5.01), and the relative width of canthal iii (2.01–2.12 versus 1.51–1.95). From P. oreistes , we distinguish P. nesobous by the relative mental width (1.96–2.18 versus 1.54–1.90), the relative nasal height (1.12–1.14 versus 0.878–1.06), and the relative nasal width (1.69–1.71 versus 1.37–1.65). From P. psychonothes , we distinguish P. nesobous by the total lamellae on one hand (50–59 versus 37–44), the relative length of digits on one hindlimb (35.1 versus 26.5–33.1), the relative largest supraocular width (2.85–3.11 versus 1.92–2.68), the relative longest finger length (6.19–6.33 versus 4.89–5.81), the relative frontal width (60.8–63.5 versus 66.5–81.0), the relative angled subocular height (0.669 –0.750 versus 0.803 –0.952), and the relative angled subocular width (2.61–2.82 versus 2.01–2.44). From P. saonae , we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus absent), the longitudinal paramedian lines (present versus absent), the total lamellae on one hand (50–59 versus 40–42), the relative length of digits on one hindlimb (35.1 versus 26.5–29.8), the relative eye length (3.41–3.63 versus 3.06–3.20), the relative forelimb length (23.3–25.1 versus 19.0–20.2), the relative ear width (1.39–1.60 versus 0.880–1.35), and the relative head length (17.9–19.8 versus 15.4–17.5). From P. semitaeniatus sp. nov., we distinguish P. nesobous by the total lamellae on one hand (50–59 versus 34–46), the relative length of digits on one hindlimb (35.1 versus 30.4–34.6), the relative ear width (1.39–1.60 versus 1.90–2.30), the relative rostral height (2.26–2.38 versus 2.41–2.63), the relative longest finger length (6.19–6.33 versus 5.17–6.05), the relative distance between the ear and eye (7.91–10.0 versus 6.64–7.90), the relative head width (71.2–76.4 versus 58.8– 63.8), and the relative frontal width (60.8–63.5 versus 63.6–76.5). From P. unicolor sp. nov., we distinguish P. nesobous by the dorsal pattern (irregular dots/dots in series versus absent) and the total lamellae on one hand (50–59 versus 48).

Description of holotype. MCZ R-77153.A young adult; SVL 78.9 mm; tail nearly cylindrical, broken at tip, 86.5 mm (110% SVL); axilla-to-groin distance 42.4 mm (53.7% SVL); forelimb length 18.9 mm (24.0% SVL); hindlimb length 29.4 mm (37.3% SVL); head length 15.6 mm (19.8% SVL); head width 10.5 mm (13.3% SVL); head width 67.3% head length; diameter of orbit 2.72 mm (3.45% SVL); horizontal diameter of ear opening 1.03 mm (1.31% SVL); vertical diameter of ear opening 1.07 mm (1.36% SVL); length of all toes on one foot 31.2 mm (39.5% SVL); shortest distance between angled subocular and lip 0.56 mm (0.710% SVL); shortest distance between the ocular and auricular openings 7.38 mm (9.35% SVL); longest finger length 5.00 mm (6.34% SVL); largest supraocular width 1.99 mm (2.52% SVL); cloacal width 6.48 mm (8.21% SVL); mental width 1.73 mm (2.19% SVL); postmental width 2.11 mm (2.67% SVL); prefrontal width 3.59 mm (4.55% SVL); frontal width 73.5% frontal length; nasal height 0.88 mm (1.12% SVL); angled subocular height 0.58 mm (0.735% SVL); shortest distance between the eye and naris 4.41 mm (5.59% SVL); canthal iii width 1.73 mm (2.19% SVL); angled subocular width 2.14 mm (2.71% SVL); nasal width 1.40 mm (1.77% 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 an irregular posterior margin, much wider than long, bordered by posterior internasals, 1 st loreals, 1 st and 2 nd 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 just posterior to 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 –5 th supralabial (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)/lower preocular (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)/1 st median ocular, anterior supraciliary, upper and lower preoculars, and 1 st and 2 nd loreals (right); 9 median oculars (left)/(right), 1 st and 2 nd 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); 11 (left)/10 (right) supralabials, 7 to level below center of eye (left)/(right); 11 infralabials (left)/(right), 7 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; 3 rd –5 th pairs separated by 1–5 scales; 91 transverse rows of dorsal scales from interoccipital to base of tail; 93 transverse rows of ventral scales from mental to vent; 39 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 13 lamellae under longest finger (left)/(right); 50 total lamellae on one hand; toe lengths 4>3>5>2>1; 18 (left)/19 (right) lamellae under longest toe; keelless and striate dorsal body and caudal scales; striate ventral scales; 173 total strigae counted on ten scales.

FIGURE 71. (A–F) Panolopus nesobous (MCZ R-77153, holotype), SVL 78.9 mm. FIGURE 72. Panolopus nesobous (ANSP 38583, SBH 269457), in life. From Ile-a-Vache, Sud Department, Haiti. Photo by SBH.

Color (in alcohol): dorsal surface of head medium brown, patternless; lateral surfaces of head grading from medium brown to dark cream with darker brown eye masks; dorsal surfaces of the body are medium brown with some darker brown spots in longitudinal paramedian series and irregular darker brown flecks on body; dorsal surface of tail are paler brown than the body with some darker brown flecks; lateral areas grade from dark brown to yellow-cream with darker brown and off-white spots arranged in bars; dorsal surfaces of the limbs are medium brown with darker brown mottling; lateral and ventral areas of the limbs grading from medium brown to yellow-cream; ventral surfaces of the head, body, and tail are cream, patternless.

Variation. Much of the examined material resembles the holotype in dorsal pattern with irregular flecks or dots. In ANSP 38581, these dots are arranged vaguely into chevrons. All specimens have either longitudinal paramedian lines or dots in the longitudinal paramedian series. All specimens have 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 nesobous is distributed on Île-à-Vache of Haiti and in inland areas near Caye Michele at elevations of 0–1160 m (Fig. 50).

Ecology and conservation. No ecological data are associated with this species. We consider the conservation status of Panolopus nesobous 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 species name ( nesobous ) is derived from the Greek neso - (island) and bous (cow) in reference to the type locality of this species on Île-à-Vache (Cow Island).

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

Panolopus nesobous was included in our genetic dataset and has significant support in both Bayesian and ML likelihood analyses at the crown node. The stem node that places P. nesobous outside of P. costatus and P. oreistes has a support value of 68% in our ML analysis and is not supported in our Bayesian analysis. Genomic data in Schools et al. (2022) placed P. nesobous outside of P. costatus and P. oreistes with a support value of 85% in their ML analysis, This relationship was not supported in their Bayesian analysis. Based on our timetree (Fig. 4), P. nesobous diverged from its closest relative 3.51 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). Panolopus nesobous was recognized as a distinct species by our ASAP analysis.