Panolopus lanceolatus, 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 : 170-174

Panolopus lanceolatus sp. nov.

Westcentral Smooth-scaled Forest Lizard

(Fig. 63)

Celestus costatus — Schwartz & Henderson, 1991:368 (part).

Celestus costatus — Powell et al., 1999:104 (part).

Celestus costatus — Hedges et al., 2019:16 (part).

Panolopus costatus — Schools & Hedges, 2021:230 (part).

Panolopus costatus — Landestoy et al., 2022:205 (part).

Holotype. MCZ R-190692, an adult female from first and only major intersection between Ennery and Plaisance, a couple hundred meters E on intersecting road, collected by D. Luke Mahler and Richard E. Glor on 6 August 2009 (19.52387, -72.45154; 925 m).

Paratypes (n=8). HAITI. Artibonite. KU 226436–9 , 1.2 mi W Ennery , 1977 . Nord. MCZ R-63383–4, Austin Stanley Rand and James Draper Lazell, Dondon , 16 July 1960 ; MCZ R-63386, Austin Stanley Rand, James Draper Lazell, Jr., Jean Bernard between Cap Haitien and Grande Riviere du Nord , 16 July 1960 ; MCZ R-190691, D. Luke Mahler, Richard E. Glor, first and only major intersection between Ennery and Plaisance , couple hundred meters E on intersecting road, 6 August 2009 .

Diagnosis. Panolopus lanceolatus sp. nov. has (1) a dorsal pattern of absent/irregular dots/dots in series/dots in chevrons, (2) head markings absent/present, (3) markings in the longitudinal paramedian area present, (4) dots arranged in bars in the lateral band present, (5) an adult SVL of 78.5–104 mm, (6) ventral scale rows, 93–102, (7) midbody scale rows, 37–43, (8) total lamellae on one hand, 41–52, (9) total strigae on ten scales, 186–234, (10) relative length of all digits on one hindlimb, 28.4–35.9 %, (11) relative distance between the angled subocular and mouth, 0.567 –0.704 %, (12) relative eye length, 3.01–3.51 %, (13) relative forelimb length, 17.4–23.9 %, (14) relative ear width, 0.770–1.35 %, (15) relative rostral height, 1.78–2.28 %, (16) relative head length, 15.2–18.2 %, (17) relative mental width, 1.45–1.96 %, (18) relative postmental width, 2.36–2.66 %, (19) relative cloacal width, 8.01–8.76 %, (20) relative prefrontal width, 3.97–4.55 %, (21) relative largest supraocular width, 2.20–2.71 %, (22) relative longest finger length, 4.76–6.36 %, (23) relative distance between the ear and eye, 6.45–7.70 %, (24) relative head width, 68.0–77.6 %, (25) relative frontal width, 63.1–72.1 %, (26) relative nasal height, 0.904–1.06 %, (27) relative angled subocular height, 0.484 –0.854 %, (28) relative distance between the eye and naris, 4.58–5.05 %, (29) relative canthal iii length, 1.73–2.00 %, (30) relative angled subocular width, 2.38–3.09 %, and (31) relative nasal length, 1.48–1.95 %. No genetic data are available for estimating the species stem time or crown time.

We distinguish Panolopus lanceolatus sp. nov. from the other species of Panolopus based on a complex of traits. From Panolopus aenetergum , we distinguish P. lanceolatus sp. nov. by the longitudinal paramedian lines (present versus absent), the ventral scale rows (93–102 versus 80–86), the midbody scale rows (37–43 versus 35–36), the total lamellae on one hand (41–52 versus 40), the total strigae on ten scales (186–234 versus 267), the relative length of digits on one hindlimb (28.4–35.9 versus 26.8), the relative distance between angled subocular and mouth (0.567 – 0.704 versus 0.717), the relative cloacal width (8.01–8.76 versus 7.60), the relative distance between the ear and eye (6.45–7.70 versus 8.40), the relative frontal width (63.1–72.1 versus 88.2), the relative nasal height (0.904–1.06 versus 1.15), the relative angled subocular height (0.484 –0.854 versus 1.08), the relative distance between the eye and naris (4.58–5.05 versus 4.35), and the relative angled subocular width (2.38–3.09 versus 2.07). From P. aporus , we distinguish P. lanceolatus sp. nov. by the relative largest supraocular width (2.20–2.71 versus 2.74–3.62) and the relative nasal height (0.904–1.06 versus 1.08–1.23). From P. chalcorhabdus , we distinguish P. lanceolatus sp. nov. by the angled subocular height (3.29–5.91 versus 2.77–3.28) (see Remarks). From P. costatus , we distinguish P. lanceolatus sp. nov. by the relative distance between the eye and naris (4.58–5.05 versus 5.08–5.50). From P. curtissi , we distinguish P. lanceolatus sp. nov. by the dots arranged in bars in the lateral areas (present versus absent), the total lamellae on one hand (41–52 versus 32–39), the relative length of digits on one hindlimb (28.4–35.9 versus 20.8–28.1), and the relative longest finger length (4.76–6.36 versus 3.59–4.54). From P. diastatus , we distinguish P. lanceolatus sp. nov. by the longitudinal paramedian lines (present versus absent) and the relative length of digits on one hindlimb (28.4–35.9 versus 21.5–27.4). From P. emys , we distinguish P. lanceolatus sp. nov. by the total strigae on ten scales (186–234 versus 238–311) and the relative angled subocular width (2.38–3.09 versus 2.12–2.20). From P. hylonomus , we distinguish P. lanceolatus sp. nov. by the dots arranged in bars in the lateral areas (present versus absent), the adult SVL (78.5–104 versus 59.3–76.5), the relative length of digits on one hindlimb (28.4–35.9 versus 22.8–28.2), and the relative postmental width (2.36–2.66 versus 2.67–2.89). From P. lapierrae sp. nov., we distinguish P. lanceolatus sp. nov. by the relative postmental width (2.36–2.66 versus 2.68–3.58), the relative prefrontal width (3.97–4.55 versus 4.73–4.75), the relative longest finger length (4.76–6.36 versus 4.49–4.55), the relative distance between the ear and eye (6.45–7.70 versus 7.78–8.43), the relative head width (68.0–77.6 versus 77.7–78.1), the relative frontal width (63.1–72.1 versus 77.6–79.0), and the relative distance between the eye and naris (4.58–5.05 versus 5.21). From P. leionotus , we distinguish P. lanceolatus sp. nov. by the frontal width by the SVL (3.48–3.84 versus 3.89–5.00) (see Remarks). From P. marcanoi , we distinguish P. lanceolatus sp. nov. by the relative nasal height (0.904–1.06 versus 1.07–1.28). From P. melanchrous , we distinguish P. lanceolatus sp. nov. by the relative postmental width (2.36–2.66 versus 2.71–3.38). From P. neiba , we distinguish P. lanceolatus sp. nov. by the frontal width by the SVL (3.48–3.84 versus 3.86–4.52) (see Remarks). From P. nesobous , we distinguish P. lanceolatus sp. nov. by the relative ear width (0.770–1.35 versus 1.39–1.60), the relative postmental width (2.36– 2.66 versus 2.82–3.02), the relative prefrontal width (3.97–4.55 versus 4.74–4.81), the relative largest supraocular width (2.20–2.71 versus 2.85–3.11), the relative distance between the ear and eye (6.45–7.70 versus 7.91–10.0), the relative nasal height (0.904–1.06 versus 1.12–1.14), the relative distance between the eye and naris (4.58– 5.05 versus 5.62–5.73), and the relative width of canthal iii (1.73–2.00 versus 2.01–2.12). From P. oreistes , we distinguish P. lanceolatus sp. nov. by the relative distance between the eye and naris (4.58–4.98 versus 5.01–5.63). From P. psychonothes , we distinguish P. lanceolatus sp. nov. by the relative nasal height (0.904–1.06 versus 1.12– 1.32). From P. saonae , we distinguish P. lanceolatus sp. nov. by the longitudinal paramedian lines (present versus absent), the relative largest supraocular width (2.20–2.71 versus 2.77), the relative frontal width (63.1–72.1 versus 72.5), the relative distance between the eye and naris (4.58–5.05 versus 6.43), and the relative angled subocular width (2.38–3.09 versus 2.31). From P. semitaeniatus sp. nov., we distinguish P. lanceolatus sp. nov. the relative ear width (0.770–1.35 versus 1.90–2.30), the relative rostral height (1.78–2.28 versus 2.41–2.63), the relative head width (68.0–77.6 versus 58.8–63.8), and the relative nasal height (0.904–1.06 versus 1.08). From P. unicolor sp. nov., we distinguish P. lanceolatus sp. nov. by the adult SVL (78.5–104 versus 67.6), the total strigae on ten scales (186–234 versus 144), the relative length of digits on one hindlimb (28.4–35.9 versus 36.8), the relative distance between angled subocular and mouth (0.567 –0.704 versus 0.533), the relative ear width (0.770–1.35 versus 1.60), the relative postmental width (2.36–2.66 versus 2.80), the relative cloacal width (8.01–8.76 versus 7.61), the relative prefrontal width (3.97–4.55 versus 4.69), the relative largest supraocular width (2.20–2.71 versus 3.12), the relative longest finger length (4.76–6.36 versus 6.65), the relative frontal width (63.1–72.1 versus 58.2), the relative nasal height (0.904–1.06 versus 1.15), the relative distance between the eye and naris (4.58–5.05 versus 5.52), and the relative nasal width (1.48–1.95 versus 2.00).

Description of holotype. MCZ R-190692. An adult female; SVL 95.1 mm; tail nearly cylindrical, 106 mm (111% SVL); axilla-to-groin distance 56.3 mm (59.2% SVL); forelimb length 20.6 mm (21.7% SVL); hindlimb length 31.0 mm (32.6% SVL); head length 16.3 mm (17.1% SVL); head width 11.2 mm (11.8% SVL); head width 68.7% head length; diameter of orbit 3.29 mm (3.46% SVL); horizontal diameter of ear opening 1.03 mm (1.08% SVL); vertical diameter of ear opening 1.18 mm (1.24% SVL); length of all toes on one foot 31.8 mm (33.4% SVL); shortest distance between angled subocular and lip 0.67 mm (0.705% SVL); shortest distance between the ocular and auricular openings 6.67 mm (7.01% SVL); longest finger length 5.66 mm (5.95% SVL); largest supraocular width 2.34 mm (2.46% SVL); cloacal width 7.62 mm (8.01% SVL); mental width 1.63 mm (1.71% SVL); postmental width 2.24 mm (2.36% SVL); prefrontal width 3.78 mm (3.97% SVL); frontal width 70.8% frontal length; nasal height 0.92 mm (0.967% SVL); angled subocular height 0.46 mm (0.484% SVL); shortest distance between the eye and naris 4.74 mm (4.98% SVL); canthal iii width 1.72 mm (1.81% SVL); angled subocular width 2.72 mm (2.86% SVL); nasal width 1.46 mm (1.54% SVL); rostral 2.28X 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, wider than long, bordered by posterior internasals, 1 st loreals, 1 st median oculars, 2 nd median ocular on the left, 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 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)/ (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); 10 (left)/9 (right) median oculars, 1 st and 2 nd contacting the prefrontal (left)/1 st (right); 1 (left)/2 (right) upper preoculars; an irregular anterior supraciliary (left)/(right); 6 (left)/5 (right) lateral oculars; 5 temporals (left)/(right); 1 subocular (left)/(right); posterior subocular large and elongate (left)/(right); 9 supralabials (left)/(right), 6 to level below center of eye (left)/(right); 9 (left)/10 (right) infralabials, 6 (left)/7 (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 1–3 scales; 94 transverse rows of dorsal scales from interoccipital to base of tail; 98 transverse rows of ventral scales from mental to vent; 37 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 13 (left)/14 (right) lamellae under longest finger; 52 total lamellae on one hand; toe lengths 4>3>2>5>1; 17 (left)/18 (right) lamellae under longest toe; keelless and striate dorsal body and caudal scales; striate ventral scales; 234 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 pale gray with darker brown eye masks and markings on the labial scales; dorsal surfaces of the body are the same medium brown as the head with several darker brown spots in the longitudinal paramedian area; dorsal surface of tail the same as the head and body; lateral areas grading from medium brown to gray-cream with darker and paler dots arranged in bars in the lateral area; dorsal surfaces of the limbs are dark brown with some paler mottling; lateral and ventral areas of the limbs fading from dark brown to pale cream with some darker brown flecks; ventral surfaces of the head, body, and tail are gray-cream with a few darker spots on the chest.

Variation. Members of this species resemble the holotype in pattern with specimens possessing irregular dots or dots occurring in and extension of the longitudinal paramedian markings or arranged in chevrons. Only KU 226436 lacks a dorsal pattern outside of longitudinal paramedian markings. Only MCZ R-63383 has head scales with dark outlines, all others have patternless heads. All specimens possess dots arranged in series in the longitudinal paramedian area or broken longitudinal paramedian lines. All specimens have dots arranged in bars in the lateral area (this trait is reduced in KU 226436 and KU 226438 ). Measurements and other morphological data for the holotype and other examined material are presented in Table 1 .

Distribution. Panolopus lanceolatus sp. nov. is distributed in northcentral Haiti to the northern coast at elevations of 20–900 m (Fig. 50).

Ecology and conservation. Little ecological information is available for this species other than that the individuals collected at 900 m are accompanied with the field notes “rock wall.”

We consider the conservation status of Panolopus lanceolatus 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. Ovoviviparous. MCZ R-63383 has developed embryos whereas MCZ R-63384 has follicles.

Etymology. The species name ( lanceolatus ) is a feminine Latin adjective, meaning spear-like, referring to the flat and pointed head of this species.

Remarks. When several animals were collected in 1960, they were identified as Panolopus diastatus in museum collections because they were captured near the range of that species. Given the morphological differences between this species and P. diastatus (the longitudinal paramedian lines present versus absent) and the relative length of digits on one hindlimb (28.4–35.9 versus 21.5–27.4) we are confident that these specimens are not that species. Schwartz (1964) plotted several locations for “ Celestus ” (Panolopus) costatus in that general vicinity, with question marks, but did not discuss them. Later, Schwartz & Henderson (1988) mentioned in the remarks section for that species that “specimens of C. costatus from northern Haiti (Dondon; Jean Bernard between Cap-Haitien and Grande Rivière du Nord)…remain unassigned subspecifically.” We believe that they are referring to the specimens that we describe herein as P. lanceolatus sp. nov.

FIGURE 63. (A–F) Panolopus lanceolatus sp. nov. (MCZ R-190692, holotype), SVL 95.1 mm.

Panolopus lanceolatus and P. chalcorhabdus cannot be morphologically separated based on our standard suite of characters; however, they can be separated by the angled subocular width divided by the angled subocular height (3.29–5.91 [n=7] versus 2.77–3.28 [n=5]). Panolopus lanceolatus sp. nov. and P. leionotus cannot be morphologically separated based on our standard suite of characters; however, they can be separated by the frontal width divided by the SVL (3.48–3.84 [n=8] versus 3.89–5.00 [n=5]). Panolopus lanceolatus sp. nov. and P. neiba cannot be morphologically separated based on our standard suite of characters; however, they can be separated by the frontal width divided by the SVL (3.48–3.84 [n=8] versus 3.86–4.52 [n=5]).

Panolopus lanceolatus sp. nov. is not included in our genetic dataset and future studies should be conducted to obtain additional specimens for better definition of the range of the species, and to obtain genetic or genomic data from this species to clarify its relationship with other species.