Caribicus anelpistus ( Schwartz et al. 1979 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 26-30

Caribicus anelpistus ( Schwartz et al. 1979)

Altagracia Giant Forest Lizard

(Fig. 6)

Diploglossus anelpistus Schwartz et al., 1979:3 . Holotype: USNM 197336 , collected by Miguel A. Jardines at Ingenio Catarey, San Cristobal, Dominican Republic, on 21 July 1977 (18.686, -70.178; 172 m).

Diploglossus anelpistus — Schwartz & Henderson, 1991:402.

Celestus anelpistus —Powell et al., 1996:65.

Celestus warreni anelpistus — Hallermann & Böhme, 2002:169.

Celestus anelpistus — Hedges et al., 2019:16.

Caribicus anelpistus — Schools & Hedges, 2021:218.

Caribicus anelpistus — Landestoy et al., 2022:204.

Material examined (n=8). DOMINICAN REPUBLIC. San Cristobal. KU 227505 , KU 227506–11 , USNM 197336 , Miguel A. Jardines, Villa Altagracia, Ingenio Catarey, ‘ Come Hombre ,’ 21 July 1977 .

Diagnosis. Caribicus anelpistus has (1) a dorsal pattern of bands, (2) head markings present, (3) markings in the longitudinal paramedian area absent/present, (4) dots arranged in bars in the lateral band absent, (5) an adult SVL of 279 mm, (6) ventral scale rows, 81–107, (7) midbody scale rows, 33–40, (8) total lamellae on one hand, 43–48, (9) total strigae on ten scales, 471, (10) relative length of all digits on one hindlimb, 24.6 %, (11) relative distance between the angled subocular and mouth, 1.24 %, (12) relative eye length, 3.69 %, (13) relative forelimb length, 21.0 %, (14) relative ear width, 1.15 %, (15) relative rostral height, 2.03 %, (16) relative head length, 23.8 %, (17) relative mental width, 1.82 %, (18) relative postmental width, 3.87 %, (19) relative cloacal width, 10.8 %, (20) relative prefrontal width, 5.38 %, (21) relative largest supraocular width, 2.31 %, (22) relative longest finger length, 4.98 %, (23) relative distance between the ear and eye, 10.6 %, (24) relative head width, 77.0 %, (25) relative frontal width, 89.3 %, (26) relative nasal height, 1.11 %, (27) relative angled subocular height, 1.89 %, (28) relative distance between the eye and naris, 5.23 %, (29) relative canthal iii length, 1.64 %, (30) relative angled subocular width, 2.27 %, and (31) relative nasal length, 1.80 %. No genetic data are available for estimating the species stem time or crown time.

Caribicus anelpistus has the smallest relative length of digits on one hindlimb (24.6), relative auricular length (1.15), and relative canthal iii length (1.64) of the genus. This species also has the largest relative head length (23.8), relative postmental width (3.87), relative cloacal width (10.8), relative distance between the ear and eye (10.6), relative frontal width (89.3), and relative angled subocular height (1.89) of the genus.

From Caribicus darlingtoni , we distinguish C. anelpistus by the dorsal pattern (bands versus lineate), the adult SVL (279 versus 61.1–74.9), the total lamellae on one hand (43–48 versus 33–39), the total strigae on ten scales (471 versus 90–120), the relative length of digits on one hindlimb (24.6 versus 26.1–31.9), the relative distance between angled subocular and mouth (1.24 versus 0.768–1.13), the relative ear width (1.15 versus 1.17–1.85), the relative head length (23.8 versus 17.4–20.0), the relative mental width (1.82 versus 2.05–2.52), the relative postmental width (3.87 versus 2.70–3.21), the relative cloacal width (10.8 versus 7.08–8.48), the relative largest supraocular width (2.31 versus 2.70–3.12), the relative distance between the ear and eye (10.6 versus 6.83–8.58), the relative frontal width (89.3 versus 74.3–80.7), the relative nasal height (1.11 versus 1.14–1.45), the relative angled subocular height (1.89 versus 0.810–1.05), and the relative width of canthal iii (1.64 versus 1.68–2.03). From C. warreni , we distinguish C. anelpistus by the relative length of digits on one hindlimb (24.6 versus 27.0–27.3), the relative ear width (1.15 versus 1.20–1.88), and the relative rostral height (2.03 versus 1.55–1.99).

Description of holotype. USNM 197336. An adult male; SVL 279 mm; tail laterally compressed, broken in life and partially regenerated, 109 mm (39.1% SVL); axilla-to-groin distance 158 mm (56.6% SVL); forelimb length 58.6 mm (21.0% SVL); hindlimb length 78.5 mm (28.1% SVL); head length 66.5 mm (23.8% SVL); head width 51.2 mm (18.4% SVL); head width 77.0% head length; diameter of orbit 10.3 mm (3.69% SVL); horizontal diameter of ear opening 3.20 mm (1.15% SVL); vertical diameter of ear opening 3.17 mm (1.14% SVL); length of all toes on one foot 68.7 mm (24.6% SVL); shortest distance between angled subocular and lip 3.46 mm (1.24% SVL); shortest distance between the ocular and auricular openings 29.6 mm (10.6% SVL); longest finger length 13.9 mm (4.98% SVL); largest supraocular width 6.45 mm (2.31% SVL); cloacal width 30.1 mm (10.8% SVL); mental width 5.09 mm (1.82% SVL); postmental width 10.8 mm (3.87% SVL); prefrontal width 15.0 mm (5.38% SVL); frontal width 89.3% frontal length; nasal height 3.10 mm (1.11% SVL); angled subocular height 5.26 mm (1.89% SVL); shortest distance between the eye and naris 14.6 mm (5.23% SVL); canthal iii width 4.57 mm (1.64% SVL); angled subocular width 6.32 mm (2.27% SVL); nasal width 5.01 mm (1.80% SVL); rostral width 2.03X as wide as high, barely 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 straight posterior margin, much wider than long, bordered by posterior internasals, additional scale separating the postnasal and the 1 st loreal (left), 1 st loreals, canthal iii, 1 st median oculars, and the frontal; frontal barely longer than wide; a pair of frontoparietals, separated by the posterior prolongation of the frontal and the interparietal plate; interparietal plate much smaller than parietals and separating them, posteriorly touching the interoccipital, which is approximately as wide as 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 (left)/3 (right) loreals; 1 st loreal higher than wide (left)/(right), in contact with postnasal, two smaller scales separating it from the postnasal, prefrontal/frontonasal complex, canthal iii, 2 nd loreal, and two additional scales that separate the tops of the 3 rd –5 th supralabials (left)/postnasal, posterior internasal, prefrontal/ frontonasal complex, canthal iii, 2 nd and 3 rd loreal, supralabial 3, and an additional scale that separates the 3 rd –4 th supralabials (right); 2 nd loreal shorter than 1 st, higher than wide (left)/shorter than 1 st, irregular (right), excluded from contact with supraocular by canthal iii (left); 3 rd loreal irregular, excluded from contact with supraocular by canthal iii (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, prefrontal/frontonasal complex, and 1 st –2 nd loreals (left)/1 st median ocular, anterior supraciliary, upper preocular, prefrontal/frontonasal complex, and the 1 st –3 rd loreals (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 (left)/7 (right) lateral oculars; 5 temporals (left)/(right); 2 suboculars (left)/(right); posterior subocular large and elongate (left)/(right); anterior subocular small (left)/(right); 11 (left)/9 (right) supralabials, 7 (left)/6 (right) to level below center of eye; 12 (left)/10 (right) infralabials, 6–7 (left)/6 (right) to level below center of eye; mental small, followed by a single, slightly larger postmental; 4 pairs of enlarged chin shields; 1 st pair in contact with one another; 2 nd –4 th pairs separated by 1–4 scales; 93 transverse rows of dorsal scales from interoccipital to base of tail; 93 transverse rows of ventral scales from mental to vent; 40 scales around midbody; 5 digits; finger lengths 3>4>2>5>1; 11 lamellae under longest finger (left)/(right); 45 total lamellae on one hand; toe lengths 4>3>5>2>1; 17 lamellae under longest toe (left)/(right); striate with a median keel on dorsal body and caudal scales; smooth ventral scales; 471 total strigae counted on ten scales.

Color (in alcohol): dorsal surface of head medium brown with darker brown areas on scale borders; lateral surfaces of head grading from medium brown to pale gray-brown with darker brown mottling; dorsal surfaces of the body have darker markings on the neck in longitudinal paramedian lines, rest of body has darker brown bands; on the dorsal surface of tail the dark brown bands of body become one and the predominant color of the tail; lateral areas medium brown with continuations of the darker brown bands; dorsal surfaces of the limbs are dark brown with some even darker mottling; lateral and ventral areas of the limbs grade to yellow-green with darker brown mottling; ventral surfaces of the head, body, and tail are yellow-green with dark brown mottling that becomes the predominant color on the tail.

Variation. The patterns of the juveniles examined resemble that of the holotype with dark bands extending across their backs. The pale areas between the bands on the juveniles are much paler than those areas on the adult holotype. All the juveniles have darker outlines on the borders of their head scales with KU 227505 exhibiting this trait in its most reduced form. The lateral areas exhibit continuations of the dorsal pattern. Several specimens exhibit markings in the longitudinal paramedian area as faded streaks or the beginnings of longitudinal paramedian lines ( KU 227505 , 227507 , and 227511). Measurements and other morphological data for the holotype and other examined material are presented in Table 1 .

Distribution. Caribicus anelpistus is known only from the region of Villa Altagracia, San Cristóbal Province, Dominican Republic (Fig. 5).

Ecology and conservation. No information is available on the ecology of this species, other than what was recorded for the type series. The type locality was an area of broadleaf lowland forest near a creek ( Schwartz et al. 1979) that was approximately 1 km x ¼ km before clearing began. The holotype and three other adults from the type locality were collected by a bulldozer crew from the root system of a “jabilla” tree ( Hura crepitans ) as the bulldozer knocked it down; the workers and many locals reported that they had never seen these lizards before the clearing began. The living animals were reported to have been most active at night ( Schwartz et al. 1979). The bulldozer crew that unearthed the type specimen said that some locals referred to this species as “ lucias grandotas. ”

Recently, Caribicus anelpistus was rediscovered 7 km SW of Villa Altagracia ( De Jesus et al. 2023). The discovery of a single specimen occurred as farmers were clearing land to plant Cacao Trees. Locals from the area also reported seeing additional animals of the same species in the area, particularly at night. Surveys should be conducted in an effort to preserve any remaining individuals.

The IUCN Redlist ( IUCN 2023) considers the conservation status of Caribicus anelpistus to be Critically Endangered (Possibly Extinct) B1ab(iii) because “of its limited extent of occurrence (being known from a single locality) and it occurs in a single location, and any surviving population is presumed to be undergoing a continuing decline in the extent and quality of its habitat. Natural habitat at the type locality has been essentially destroyed, although if the species occurred more widely a continuing decline in the extent and quality of its habitat can be inferred.” The holotype description states that locals killed some of the lizards found with the type series ( Schwartz et al. 1979), indicating that this species may face persecution from humans. Studies are needed to determine the health of any remaining populations and threats to the survival of the species. Captive-breeding programs should be undertaken, because eradication of introduced mammalian predators is currently not possible on large islands. All mongoose-free islets of Hispaniola need to be thoroughly surveyed for the possible presence of this species.

Reproduction. Ovoviviparous. Two wild-caught females gave birth to a total of 42 young between 16 July and 3 August ( Schwartz et al. 1979).

Etymology. The species name is derived from the Greek word for “unexpected.”

FIGURE 6. (A–F) Caribicus anelpistus (USNM 197336, holotype), SVL 279 mm.

Remarks. When this species was described, it was designated as a full species, rather than a subspecies of Caribicus warreni , based on morphological traits and a distance of ~ 300 km between the type locality and the nearest C. warreni population ( Schwartz et al. 1979). Caribicus anelpistus was later designated as a subspecies of C. warreni , along with C. carraui ( Hallermann & Böhme 2002) . Later, C. anelpistus was elevated again to a full species, whereas C. carraui was placed in the synonymy of C. warreni ( Powell & Henderson 2003) .

Schwartz et al. (1979) speculated that the isolated populations of Caribicus anelpistus and C. warreni , in addition to previously discovered fossils of a large forest lizard in a cave at Cerro de San Francisco ( Etheridge 1965), suggested that the large diploglossids on Hispaniola were the relicts of an ancient, widespread population and that additional isolated populations likely existed. Caribicus anelpistus is not included in our genetic dataset and future studies should be conducted using genetic or genomic data from this species to confirm its taxonomic status.