Panolopus aenetergum ( Schwartz & Jacobs 1989 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 134-139

Panolopus aenetergum ( Schwartz & Jacobs 1989)

Isla Catalinita Forest Lizard

(Fig. 51)

Celestus costatus aenetergum Schwartz & Jacobs, 1989:193 . Holotype: USNM 197323 , an adult male, collected by Jeremy F. Jacobs and Ronald I. Crombie on Isla Catalinita, La Altagracia, Dominican Republic, on 27 July 1975 (18.195, -68.638; 0 m).

Celestus costatus aenetergum — Schwartz & Henderson, 1991:368.

Celestus costatus aenetergum — Schools & Hedges, 2021:231.

Material examined (n=1). LA ALTAGRACIA. Isla Catalinita. USNM 197323 , Jeremy F. Jacobs and Ronald I. Crombie, just south of central part of island, inland, 27 July 1975 .

Diagnosis. Panolopus aenetergum has (1) a dorsal pattern of irregular dots, (2) head markings absent, (3) markings in the longitudinal paramedian area absent, (4) dots arranged in bars in the lateral band present, (5) an adult SVL of 83.0–92.0 mm, (6) ventral scale rows, 80–86, (7) midbody scale rows, 35–36, (8) total lamellae on one hand, 40, (9) total strigae on ten scales, 267, (10) relative length of all digits on one hindlimb, 26.8 %, (11) relative distance between the angled subocular and mouth, 0.717 %, (12) relative eye length, 3.34 %, (13) relative forelimb length, 20.6 %, (14) relative ear width, 1.29 %, (15) relative rostral height, 2.09 %, (16) relative head length, 17.5 %, (17) relative mental width, 1.63 %, (18) relative postmental width, 2.62 %, (19) relative cloacal width, 7.60 %, (20) relative prefrontal width, 4.15 %, (21) relative largest supraocular width, 2.49 %, (22) relative longest finger length, 4.83 %, (23) relative distance between the ear and eye, 8.40 %, (24) relative head width, 76.4 %, (25) relative frontal width, 88.2 %, (26) relative nasal height, 1.15 %, (27) relative angled subocular height, 1.08 %, (28) relative distance between the eye and naris, 4.35 %, (29) relative canthal iii length, 1.86 %, (30) relative angled subocular width, 2.07 %, and (31) relative nasal length, 1.92 %. No genetic data are available to estimate the species stem or crown time.

Panolopus aenetergum has a smaller relative angled subocular width (2.07) and a larger relative frontal width (88.2) than most other species of the genus.

From Panolopus aporus , we distinguish P. aenetergum by the midbody scale rows (35–36 versus 37–42), the total strigae on ten scales (267 versus 150–235), the relative length of digits on one hindlimb (26.8 versus 27.7– 33.7), the relative distance between angled subocular and mouth (0.717 versus 0.441 –0.669), the relative mental width (1.63 versus 1.72–2.08), the relative cloacal width (7.60 versus 7.92–8.86), the relative prefrontal width (4.15 versus 4.18–4.53), the relative largest supraocular width (2.49 versus 2.74–3.62), the relative frontal width (88.2 versus 61.7–75.1), the relative angled subocular height (1.08 versus 0.638–1.02), the relative distance between the eye and naris (4.35 versus 4.69–5.44), the relative angled subocular width (2.07 versus 2.32–2.73), and the relative nasal width (1.92 versus 1.56–1.78). From P. chalcorhabdus , we distinguish P. aenetergum by the ventral scale rows (80–86 versus 88–97), the total strigae on ten scales (267 versus 184–233), the relative length of digits on one hindlimb (26.8 versus 31.3–36.0), the relative cloacal width (7.60 versus 7.74–9.08), the relative prefrontal width (4.15 versus 4.37–4.93), the relative largest supraocular width (2.49 versus 2.52–2.86), the relative longest finger length (4.83 versus 5.29–6.97), the relative head width (76.4 versus 65.0–76.3), the relative frontal width (88.2 versus 62.5–80.8), the relative angled subocular height (1.08 versus 0.739 –0.854), the relative distance between the eye and naris (4.35 versus 4.93–5.62), the relative width of canthal iii (1.86 versus 1.98–2.05), and the relative angled subocular width (2.07 versus 2.36–2.71). From P. costatus , we distinguish P. aenetergum the ventral scale rows (80–86 versus 89–106), the midbody scale rows (35–36 versus 39–43), the total lamellae on one hand (40 versus 49–58), the total strigae on ten scales (267 versus 158–217), the relative length of digits on one hindlimb (26.8 versus 31.5–37.8), the relative mental width (1.63 versus 1.66–2.00), the relative longest finger length (4.83 versus 5.53–6.66), the relative frontal width (88.2 versus 56.2–67.4), the relative angled subocular height (1.08 versus 0.562 –0.886), the relative distance between the eye and naris (4.35 versus 5.08–5.50), the relative angled subocular width (2.07 versus 2.36–2.81), and the relative nasal width (1.92 versus 1.58–1.74). From P. curtissi , we distinguish P. aenetergum by the dorsal pattern (irregular dots versus absent/irregular flecks), the dots arranged in bars in the lateral areas (present versus absent), the ventral scale rows (80–86 versus 90–103), the total lamellae on one hand (40 versus 32–39), the total strigae on ten scales (267 versus 165–260), the relative distance between angled subocular and mouth (0.717 versus 0.393 –0.587), the relative forelimb length (20.6 versus 15.1–20.5), the relative longest finger length (4.83 versus 3.59–4.54), the relative distance between the ear and eye (8.40 versus 5.36–7.71), the relative frontal width (88.2 versus 65.4–83.1), the relative angled subocular width (2.07 versus 2.26–2.76), and the relative nasal width (1.92 versus 1.44–1.82). From P. diastatus , we distinguish P. aenetergum by the dorsal pattern (irregular dots versus absent/irregular flecks), the total strigae on ten scales (267 versus 169– 234), the relative distance between angled subocular and mouth (0.717 versus 0.00–0.614), the relative eye length (3.34 versus 2.71–3.32), the relative forelimb length (20.6 versus 16.2–20.1), the relative head width (76.4 versus 69.4–74.8), the relative frontal width (88.2 versus 57.4–86.2), and the relative nasal width (1.92 versus 1.41–1.77). From P. emys , we distinguish P. aenetergum by the dorsal pattern (irregular dots versus absent/irregular flecks), the adult SVL (83.0–92.0 versus 99.0–113), the ventral scale rows (80–86 versus 89–104), the relative length of digits on one hindlimb (26.8 versus 28.9–35.2), the relative rostral height (2.09 versus 2.10–2.37), the relative cloacal width (7.60 versus 8.24–8.96), the relative longest finger length (4.83 versus 5.15–5.83), the relative frontal width (88.2 versus 67.7–74.5), the relative nasal height (1.15 versus 0.963–1.10), the relative angled subocular height (1.08 versus 0.696 –0.981), and the relative distance between the eye and naris (4.35 versus 4.37–5.19). From P. hylonomus , we distinguish P. aenetergum by the dorsal pattern (irregular dots versus absent/irregular flecks), the dots arranged in bars in the lateral areas (present versus absent), the adult SVL (83.0–92.0 versus 59.3–76.5), the total strigae on ten scales (267 versus 169–222), the relative postmental width (2.62 versus 2.67–2.89), the relative cloacal width (7.6 versus 7.98–8.57), the relative prefrontal width (4.15 versus 4.23–4.87), the relative largest supraocular width (2.49 versus 2.65–2.90), the relative distance between the ear and eye (8.40 versus 6.78–8.05), the relative frontal width (88.2 versus 64.0–74.5), and the relative width of canthal iii (1.86 versus 1.95–2.03). From P. lanceolatus sp. nov., we distinguish P. aenetergum by the longitudinal paramedian lines (absent versus present), the ventral scale rows (80–86 versus 93–102), the midbody scale rows (35–36 versus 37–43), the total lamellae on one hand (40 versus 41–52), the total strigae on ten scales (267 versus 186–234), the relative length of digits on one hindlimb (26.8 versus 28.4–35.9), the relative distance between angled subocular and mouth (0.717 versus 0.567 – 0.704), the relative cloacal width (7.60 versus 8.01–8.76), the relative distance between the ear and eye (8.4 versus 6.45–7.70), the relative frontal width (88.2 versus 63.1–72.1), the relative nasal height (1.15 versus 0.904–1.06), the relative angled subocular height (1.08 versus 0.484 –0.854), the relative distance between the eye and naris (4.35 versus 4.58–5.05), and the relative angled subocular width (2.07 versus 2.38–3.09). From P. lapierrae sp. nov., we distinguish P. aenetergum by the dorsal pattern (irregular dots versus absent/dots in chevrons) and the ventral scale rows (80–86 versus 90–98). From P. leionotus , we distinguish P. aenetergum by the total lamellae on one hand (40 versus 43–48), the total strigae on ten scales (267 versus 191–266), the relative mental width (1.63 versus 1.67– 2.02), the relative cloacal width (7.60 versus 8.03–8.69), the relative frontal width (88.2 versus 68.7–81.2), the relative distance between the eye and naris (4.35 versus 4.46–5.61), and the relative angled subocular width (2.07 versus 2.48–2.95). From P. marcanoi , we distinguish P. aenetergum by the head markings (absent versus present), the longitudinal paramedian lines (absent versus present), the ventral scale rows (80–86 versus 89–102), the midbody scale rows (35–36 versus 38–45), the total strigae on ten scales (267 versus 141–254), the relative mental width (1.63 versus 1.75–2.33), the relative prefrontal width (4.15 versus 4.19–5.19), the relative frontal width (88.2 versus 59.0–73.0), the relative angled subocular height (1.08 versus 0.505 –0.793), the relative distance between the eye and naris (4.35 versus 4.68–5.82), and the relative angled subocular width (2.07 versus 2.19–3.14). From P. melanchrous , we distinguish P. aenetergum by the longitudinal paramedian lines (absent versus present), the adult SVL (83.0–92.0 versus 93.2–124), the ventral scale rows (80–86 versus 89–113), the total lamellae on one hand (40 versus 47–58), the relative length of digits on one hindlimb (26.8 versus 30.7–41.3), the relative postmental width (2.62 versus 2.71–3.38), the relative cloacal width (7.60 versus 7.61–9.20), the relative prefrontal width (4.15 versus 4.21–5.06), the relative longest finger length (4.83 versus 5.76–7.09), the relative frontal width (88.2 versus 61.3– 71.4), the relative nasal height (1.15 versus 0.897 –0.952), the relative angled subocular height (1.08 versus 0.680 – 0.856), the relative distance between the eye and naris (4.35 versus 4.89–5.59), and the relative angled subocular width (2.07 versus 2.28–2.82). From P. neiba , we distinguish P. aenetergum by the dorsal pattern (irregular dots versus irregular flecks/dots in chevrons), the total lamellae on one hand (40 versus 45–49), the total strigae on ten scales (267 versus 179–239), the relative length of digits on one hindlimb (26.8 versus 29.5–36.6), the relative mental width (1.63 versus 1.66–2.36), the relative prefrontal width (4.15 versus 4.41–5.49), the relative longest finger length (4.83 versus 5.61–6.66), the relative frontal width (88.2 versus 63.3–74.0), the relative nasal height (1.15 versus 0.963–1.08), the relative angled subocular height (1.08 versus 0.713 –0.885), the relative distance between the eye and naris (4.35 versus 4.51–5.01), and the relative angled subocular width (2.07 versus 2.34–2.83). From P. nesobous , we distinguish P. aenetergum by the longitudinal paramedian lines (absent versus present), the midbody scale rows (35–36 versus 38–43), and the total lamellae on one hand (40 versus 50–59). From P. oreistes , we distinguish P. aenetergum by the longitudinal paramedian lines (absent versus present), the relative length of digits on one hindlimb (26.8 versus 31.2–40.1), the relative prefrontal width (4.15 versus 4.18–4.96), the relative longest finger length (4.83 versus 5.27–7.23), the relative frontal width (88.2 versus 61.6–76.9), the relative nasal height (1.15 versus 0.878–1.06), the relative angled subocular height (1.08 versus 0.737 –0.978), the relative distance between the eye and naris (4.35 versus 5.01–5.63), the relative angled subocular width (2.07 versus 2.13–3.04), and the relative nasal width (1.92 versus 1.37–1.65). From P. psychonothes , we distinguish P. aenetergum by the ventral scale rows (80–86 versus 88–109), the total strigae on ten scales (267 versus 172–244), the relative longest finger length (4.83 versus 4.89–5.81), the relative distance between the ear and eye (8.4 versus 6.79–8.29), the relative frontal width (88.2 versus 66.5–81.0), and the relative angled subocular height (1.08 versus 0.803 –0.952). From P. saonae , we distinguish P. aenetergum by the dorsal pattern (irregular dots versus absent), the ventral scale rows (80–86 versus 92–95), the relative distance between angled subocular and mouth (0.717 versus 0.517 –0.630), and the relative eye length (3.34 versus 3.06–3.20). From P. semitaeniatus sp. nov., we distinguish P. aenetergum by the total strigae on ten scales (267 versus 174–204), the relative length of digits on one hindlimb (26.8 versus 30.4– 34.6), the relative forelimb length (20.6 versus 21.3–23.8), the relative ear width (1.29 versus 1.90–2.30), the relative mental width (1.63 versus 1.69–2.09), the relative cloacal width (7.60 versus 8.08–8.23), the relative prefrontal width (4.15 versus 4.38–4.94), the relative largest supraocular width (2.49 versus 2.59–3.32), the relative longest finger length (4.83 versus 5.17–6.05), the relative distance between the ear and eye (8.40 versus 6.64–7.90), the relative head width (76.4 versus 58.8–63.8), the relative frontal width (88.2 versus 63.6–76.5), and the relative angled subocular height (1.08 versus 0.654).From P. unicolor sp. nov., we distinguish P. aenetergum by the dorsal pattern (irregular dots versus absent), the longitudinal paramedian lines (absent versus present), the total strigae on ten scales (267 versus 144), and the relative frontal width (88.2 versus 58.2).

Description of holotype. USNM 197323. An adult; SVL 92.0 mm; tail nearly cylindrical, broken in life midway, regenerated, 115 mm (125% SVL); axilla-to-groin distance 54.7 mm (59.5% SVL); forelimb length 19.0 mm (20.7% SVL); hindlimb length 25.7 mm (27.9% SVL); head length 16.1 mm (17.5% SVL); head width 12.3 mm (13.4% SVL); head width 76.4% head length; diameter of orbit 3.07 mm (3.34% SVL); horizontal diameter of ear opening 1.19 mm (1.29% SVL); vertical diameter of ear opening 1.44 mm (1.57% SVL); length of all toes on one foot 24.7 mm (26.8% SVL); shortest distance between angled subocular and lip 0.66 mm (0.717% SVL); shortest distance between the ocular and auricular openings 7.73 mm (8.40 SVL); longest finger length 4.44 mm (4.83% SVL); largest supraocular width 2.29 mm (2.49% SVL); cloacal width 6.99 mm (7.60% SVL); mental width 1.50 mm (1.63% SVL); postmental width 2.41 mm (2.62% SVL); prefrontal width 3.82 mm (4.15% SVL); frontal width 88.2% frontal length; nasal height 1.06 mm (1.15% SVL); angled subocular height 0.99 mm (1.08% SVL); shortest distance between the eye and naris 4.00 mm (4.35% SVL); canthal iii width 1.71 mm (1.86% SVL); angled subocular width 1.90 mm (2.07% SVL); nasal width 1.77 mm (1.92% SVL); rostral 2.09X 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 (fused with parietals); interparietal plate smaller than parietals and fused with them, posteriorly touching the interoccipital, which is wider than long; parietal separated from supraoculars by 1 st and 2 nd temporals and frontoparietal (1 st fused with the frontoparietal) (left)/1 st –3 rd temporals and frontoparietal (1 st temporal divided) (right); nasal single; nostril above suture between 1 st and 2 nd supralabials (left)/(right); postnasal 1 (left)/(right); loreals 2 (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 (fused with 1 st median ocular), additional scale above 2 nd loreal, 2 nd loreal, and 3 rd –4 th supralabials (left)/in contact with postnasal, posterior internasal, prefrontal/frontonasal complex, 1 st median ocular, canthal iii, 2 nd loreal, and 3 rd –4 th supralabials (right); 2 nd loreal shorter than 1 st, approximately as high as wide (left)/(right), excluded from contact with supraocular by canthal iii (fused with median ocular 1), additional scale above 2 nd loreal (left)/canthal iii (right); 2 nd loreal posteriorly bordering the lower preocular (left)/(right); canthal iii fused with 1 st median ocular (left)/wider than high (right), contacting 1 st median ocular (fused), anterior supraciliary, upper and lower preoculars, 1 st and 2 nd loreals, and the additional scale (left)/1st median ocular, anterior supraciliary, upper preocular, and 1 st and 2 nd loreals (right); 10 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 (left)/6 (right) temporals; 1 (left)/2 (right) suboculars; posterior subocular large and elongate (left)/(right); anterior subocular small (right); 10 (left)/9 (right) supralabials, 6 to level below center of eye (left)/(right); 10 (left)/9 (right) infralabials, 5 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 1–2 scales; 97 transverse rows of dorsal scales from interoccipital to base of tail; 86 transverse rows of ventral scales from mental to vent; 36 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 10 (left) lamellae under longest finger; 40 total lamellae on one hand; toe lengths 4>3>5>2>1; 17 (left) lamellae under longest toe; dorsal body and caudal scales keelless and striate; ventral scales with faint striations; 267 total strigae counted on ten scales.

FIGURE 51. (A–F) Panolopus aenetergum (USNM 197323, holotype), SVL 92.0 mm.

Color (in alcohol): dorsal surface of head brown-gray, patternless; lateral surfaces of head grading from brown-gray to cream with darker brown eye masks and other darker brown areas on the labial scales; dorsal surfaces of the body are brown-gray with many darker brown flecks; dorsal surface of tail the same as the body; lateral areas grade from dark brown to cream with cream and dark brown dots in rows; dorsal surfaces of the limbs are dark brown with paler gray mottling; lateral and ventral areas of the limbs grade to cream with some darker brown mottling; ventral surfaces of the head, body, and tail are cream with several flecks under the throat.

Variation. No other specimens were examined for this species. Measurements and other morphological data for the holotype are presented in Table 1.

Distribution. Panolopus aenetergum is distributed on Isla Catalinita at 0–5 m (Fig. 50).

Ecology and conservation. Both the holotype and paratype of this species were collected as they actively foraged in leaf litter during the day (0900–1130 h) in a way that the collectors believed them to be Ameiva ( Schwartz & Jacobs 1989) .

We consider the conservation status of Panolopus aenetergum 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, its range appears to be very small, which is a concern. 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 ( aenetergum ) is an appositional noun derived from the Latin aene (bronze) and tergum (back) in reference to the metallic dorsal color of this species.

Remarks. Schwartz & Jacobs (1989) noted that the fauna of Isla Catalinita, including Panolopus aenetergum , could have been derived from either the mainland or nearby Isla Saona. Panolopus aenetergum is not included in our genetic dataset and future studies should be conducted using genetic or genomic data from this species.