Guarocuyus jaraguanus ( Landestoy et al. 2022 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 130-134

Guarocuyus jaraguanus ( Landestoy et al. 2022)

Jaragua Forest Lizard

(Fig. 47)

Guarocuyus jaraguanus — Landestoy et al., 2022: 201 . Holotype: MNHNSD 23.3937 , collected by Miguel A. Landestoy from Cayo de las Iguanas, Pedernales Province, Dominican Republic on 22 September 2021 (17.73205, -71.37126; near sea level).

Material examined (n=19). DOMINICAN REPUBLIC. Pedernales. IIBZ-HER00001–00004 , MNHNSD 23.3912 – 3916 , Miguel A. Landestoy, Gerson Féliz, and Juan Pérez-Vidal, Parque Nacional Jaragua, Laguna de Oviedo Cayo de las Iguanas , 29 April 2021 ; IIBZ-HER00005–00008 , MNHNSD 23.3934 – 3936 , Miguel A. Landestoy, Parque Nacional Jaragua, Laguna de Oviedo Cayo de las Iguanas , 29 April 2021 ; MNHNSD 23.3937 , Miguel A. Landestoy, Parque Nacional Jaragua, Laguna de Oviedo, Cayo de las Iguanas , 22 September 2021 ; MNHNSD 23.3948 – 3949 , Miguel A. Landestoy and Gerson Féliz, Laguna de Oviedo, Cayo Pei , 4 June 2022 .

Diagnosis. Landestoy et al. (2022) discussed several unique morphological traits observed in Guarocuyus jaraguanus . These include the number of scales in contact with the nasal scale (ranging from 4–5), the number of postnasal scales (1–2), the semi-prehensile tail, and the presence of scaleless webbing between toes II to IV.

Guarocuyus jaraguanus has (1) a dorsal pattern of mottled/chevrons/bands, (2) head markings present, (3) markings in the longitudinal paramedian area present, (4) dots arranged in bars in the lateral band absent, (5) a maximum SVL of 84.6–110 mm, (6) ventral scale rows, 100–114, (7) midbody scale rows, 40, (8) total lamellae on one hand, unavailable, (9) total strigae on ten scales, unavailable, (10) relative length of all digits on one hindlimb, unavailable, (11) relative distance between the angled subocular and mouth, unavailable, (12) relative eye length, unavailable, (13) relative forelimb length, unavailable, (14) relative ear width, 2.33–2.90 %, (15) relative rostral height, 1.55–1.85 %, (16) relative head length, 18.6 %, (17) relative mental width, unavailable, (18) relative postmental width, unavailable, (19) relative cloacal width, unavailable, (20) relative prefrontal width, unavailable, (21) relative largest supraocular width, unavailable, (22) relative longest finger length, unavailable, (23) relative distance between the ear and eye, unavailable, (24) relative head width, 74.5 %, (25) relative frontal width, unavailable, (26) relative nasal height, unavailable, (27) relative angled subocular height, unavailable, (28) relative distance between the eye and naris, unavailable, (29) relative canthal iii length, unavailable, (30) relative angled subocular width, unavailable, and (31) relative nasal length, unavailable. The species stem time is 8.59 Ma and the species crown time is 0.01 Ma (Fig. 4).

FIGURE 47. Map showing known locality for Guarocuyus jaraguanus . Inset shows all of Hispaniola, with a red box indicating the mapped area.

Description of holotype. MNHNSD 23.3937. An adult male; SVL 96.0 mm; tail cylindrical, partially regenerated; axilla-to-groin distance 51.8 mm (54.0% SVL); head length 17.9 mm (18.6% SVL); head width 13.3 mm (13.9% SVL); head width 74.3% head length; horizontal diameter of ear opening 2.60 mm (2.71% SVL); rostral 58.3X as wide as high, barely visible from above, not in contact with nasals, in contact with 1 st supralabial and anterior internasal (left); anterior internasals are narrower than posterior ones; frontonasals and prefrontal fused into a single large plate with a straight posterior margin, much wider than long; 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; parietal separated from supraoculars by 1 st temporals and frontoparietal (left)/(right); nasal single; nostril above suture between 1 st and 2 nd supralabials (left); 1 (left)/(right) postnasal; 2 (left)/(right) loreals; 1 st loreal higher than wide (left)/; 2 nd loreal shorter than 1 st, approximately as high as wide (left) excluded from contact with supraocular by canthal iii (left); canthal iii wider than high (left); 10 (left) median oculars; 6 (left) lateral oculars; 6 (left) temporals; 10 (left)/(right) supralabials, 7 (left)/(right) to level below center of eye; mental small, followed by a single, larger postmental; 4 pairs of enlarged chin shields, followed by 1 pairs of reduced chin shields; 1 st pair in contact with one another anteriorly, posteriorly separated by one scale; 2 nd –5 th pairs separated by 1–5 scales; 91 transverse rows of dorsal scales from interoccipital to base of tail; 106 transverse rows of ventral scales from mental to vent; 40 scales around midbody; 5 (left)/4 (one missing) (right) digits; finger lengths 3>4>2>5>1; toe lengths 4>3>5>2>1; 24 lamellae under longest toe (left)/(right); dorsal body and caudal scales striate with a median keel.

Color (in alcohol): dorsal surface of head covered with mottling of various shades of brown and cream; lateral surfaces of head grading from mottled brown to cream; dorsal surfaces of the body are mottled brown with mottling arranged into bands across the body; dorsal surface of tail the same as the body; lateral areas grade from mottled brown to cream with continuations of the dorsal pattern; dorsal surfaces of the limbs are the same as the body; lateral and ventral areas of the limbs fade to light cream; ventral surfaces of the head, body, and tail are light cream, patternless.

FIGURE 48. (A–C) Guarocuyus jaraguanus (MNHNSD 23.3937, holotype), SVL 96.0 mm.

Variation. Measurements and other morphological data for the holotype and other examined material are presented in Table 1.

Distribution. Guarocuyus jaraguanus is distributed on Cayo de las Iguanas and adjacent Cayo Pei, Laguna de Oviedo, on the Barahona Peninsula of the Dominican Republic (Fig. 48).

Ecology and conservation. Members of this species have been collected exposed on the ground (rocks, leaf litter, and black mangrove roots) and under large bromeliads and agaves at and after dusk. Several were collected while foraging on dry mud within the root system of black mangroves ( Avicennia germinans ). One animal was observed 1.5 m high in epiphytic bromeliads ( Tillandsia utriculata ). All individuals were collected from 1900–2130 h, suggesting that this is a nocturnal species. Individuals with complete, non-regenerated tails exhibited semi-prehensile ability. This, coupled with the animal observed in a bromeliad indicates that this is an arboreal species ( Landestoy et al. 2022).

Guarocuyus jaraguanus was assessed as Critically Endangered (CR B2a), based on its very small distribution and threats from habitat alteration and introduced predators ( Landestoy et al. 2022), based on IUCN Redlist criteria (IUCN 2022). Studies are needed to determine the health and extent of remaining populations and threats to the survival of the species.

Reproduction. All collected females were gravid, of which only the second smallest (IIBZ-HER00004, SVL 77.5 mm) was dissected and contained a single, well-developed fetus (IIBZ-HER00012, SVL 27.8 mm).

Etymology. The species name ( jaraguanus ) is a masculine nominative singular adjective meaning “pertaining to Jaragua,” the name of the national park that encompasses the type locality.

Remarks. This species could represent an ecological equivalent of Comptus stenurus and Panolopus costatus ( Landestoy et al. 2022) . Another hypothesis proposed was that Guarocuyus jaraguanus could also represent a relic of a formerly widespread lineage. Guarocuyus jaraguanus diverged from its closest relative 8.59 Ma (Fig. 4), consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015), and was recognized as a distinct species by our ASAP analysis.

Genus Panolopus Cope, 1862b

Caribbean Smooth-scaled Forest Lizards

(Figs. 49–50)

Panolopus Cope, 1862:494 . Type species: Panolopus costatus Cope, 1862:494 , by original designation.

Diagnosis. Panolopus has (1) a dorsal pattern of absent/irregular flecks/irregular dots/dots in series/dots in chevrons, (2) head markings absent/present, (3) markings in the longitudinal paramedian area absent/present, (4) dots arranged in bars in the lateral band absent/present, (5) a maximum SVL of 59.3–113 mm, (6) ventral scale rows, 77– 114, (7) midbody scale rows, 32–45, (8) total lamellae on one hand, 32–59, (9) total strigae on ten scales, 141–413, (10) relative length of all digits on one hindlimb, 20.8–41.3 %, (11) relative distance between the angled subocular and mouth, 0.00–1.17 %, (12) relative eye length, 2.36–4.01 %, (13) relative forelimb length, 15.1–27.6 %, (14) relative ear width, 0.558–2.39 %, (15) relative rostral height, 1.40–2.88 %, (16) relative head length, 10.2–22.5 %, (17) relative mental width, 1.33–2.91 %, (18) relative postmental width, 2.07–3.58 %, (19) relative cloacal width, 7.13–9.65 %, (20) relative prefrontal width, 3.74–5.49 %, (21) relative largest supraocular width, 1.88–3.62 %, (22) relative longest finger length, 3.48–7.23 %, (23) relative distance between the ear and eye, 5.36–10.0 %, (24) relative head width, 58.8–85.0 %, (25) relative frontal width, 56.2–88.2 %, (26) relative nasal height, 0.854–1.55 %, (27) relative angled subocular height, 0.484–1.33 %, (28) relative distance between the eye and naris, 4.00–6.43 %, (29) relative canthal iii length, 1.16–2.70 %, (30) relative angled subocular width, 1.61–3.14 %, and (31) relative nasal length, 1.23–2.09 %.

Content. Twenty species (Table 3): Panolopus aenetergum , P. aporus , P. chalcorhabdus , P. costatus , P. curtissi , P. diastatus , P. emys , P. hylonomus , P. lanceolatus sp. nov., P. lapierrae sp. nov., P. leionotus , P. marcanoi , P. melanchrous , P. neiba , P. nesobous , P. oreistes , P. psychonothes , P. saonae , P. semitaeniatus sp. nov., and P. unicolor sp. nov.

Distribution: Panolopus occurs on Hispaniola and some surrounding islets.

FIGURE 49. Map showing the distribution of nine species of Panolopus in Hispaniola. Hollow symbols indicate unexamined records.

FIGURE 50. Map showing the distribution of eleven species of Panolopus in Hispaniola. Hollow symbols indicate unexamined records assignable to species.