Wetmorena mylica ( Schwartz 1965 )

Schools, Molly & Hedges, Blair, 2024, A new forest lizard fauna from Caribbean islands (Squamata, Diploglossidae, Celestinae), Zootaxa 5554 (1), pp. 1-306 : 263-267

Wetmorena mylica ( Schwartz 1965)

Barahona Earless Forest Lizard

(Fig. 100–101)

Wetmorena haetiana mylica Schwartz, 1965:45 . Holotype: MCZ R-77049, collected by David C. Leber and A. Thomas from 24 km SW Barahona, Barahona province, Dominican Republic, on 2 August 1963.

Wetmorena haetiana mylica — Schwartz & Henderson, 1991:553.

Celestus haetianus mylica — Henderson & Powell, 2009:103.

Celestus haetianus mylicus — Hedges et al., 2019:17.

Material examined (n=26). DOMINICAN REPUBLIC. Barahona. AMNH 92086–7 , D. C. Leber & Richard Thomas, 8 km NE Las Auyamas , 28 July 1963 ; AMNH 92088 , D. C. Leber & Richard Thomas, 24 km SW Barahona , 2 August 1963 ; KU 228144–50 , 24 km SW Barahona , 2 August 1963 ; MCZ R-77049, David C. Leber, A. Thomas, 24 km SW Barahona , 2 August 1963 ; USNM 150554–7 , Barahona , 24 km SW of, 2 August 1963 ; USNM 328854–5 , 328857 , 328863 , 328865 , 328871–2 , 328875–6 , 328878 , 328881 , Richard Thomas and S. Blair Hedges, 15.3 km S, 6.7 km E (road) of Cabral, 16 August 1284 .

Diagnosis. Wetmorena mylica has (1) a dorsal pattern of absent/irregular dots, (2) head markings absent/present, (3) markings in the longitudinal paramedian area absent/present, (4) dots arranged in bars in the lateral band absent, (5) a maximum SVL of 76.0– 98.2 mm, (6) ventral scale rows, 112–126, (7) midbody scale rows, 37–41, (8) total lamellae on one hand, 16–23, (9) total strigae on ten scales, 84–105, (10) relative length of all digits on one

FIGURE 100. (A–F) Wetmorena mylica (MCZ R-77049, holotype), SVL 85.3 mm.

FIGURE 101. Wetmorena mylica (USNM 328895, SBH 160207), in life. From ca. 2 km S Tejunde, Barahona Province, Dominican Republic. Photograph by SBH.

hindlimb, 9.62–15.5 %, (11) relative distance between the angled subocular and mouth, 0.00–0.504 %, (12) relative eye length, 2.13–2.97 %, (13) relative forelimb length, 10.5–14.3 %, (14) relative ear width, 0.00 %, (15) relative rostral height, 1.76–2.37 %, (16) relative head length, not applicable, (17) relative mental width, 1.34–1.95 %, (18) relative postmental width, 2.02–2.91 %, (19) relative cloacal width, 5.90–7.07 %, (20) relative prefrontal width, 3.26–4.01 %, (21) relative largest supraocular width, 1.62–2.97 %, (22) relative longest finger length, 2.43–2.95 %, (23) relative distance between the ear and eye, not applicable, (24) relative head width, not applicable, (25) relative frontal width, 84.8–114 %, (26) relative nasal height, 0.850–1.13 %, (27) relative angled subocular height, 1.09– 1.50 %, (28) relative distance between the eye and naris, 3.10–3.67 %, (29) relative canthal iii length, 0.956–1.15 %, (30) relative angled subocular width, 1.74–2.29 %, and (31) relative nasal length, 1.23–1.65 %. The species stem time is 4.25 Ma and the species crown time is 0.43 Ma (Fig. 4).

We distinguish Wetmorena mylica from the other species of Wetmorena based on a complex of traits. From Wetmorena agasepsoides , we distinguish W. mylica by the dorsal pattern (absent/irregular dots versus absent), the adult SVL (76.0–98.2 versus 49.1–58.6), the midbody scale rows (37–41 versus 27–31), the relative forelimb length (10.5–14.3 versus 8.05–9.58), the relative ear width (0.00 versus 0.292 –0.634), and the relative longest finger length (2.43–2.95 versus 1.44–2.01). From W. haetiana , we cannot distinguish W. mylica based on our standard suite of characters, but the two taxa can be separated by ventral coloration: dark brown in W. haetiana versus cream in W. mylica , as noted by Schwartz (1965). From W. obscura sp. nov., we distinguish W. mylica by the dorsal pattern (absent/irregular dots versus lineate), the adult SVL (76.0–98.2 versus 46.9–61.1), the ventral scale rows (112–126 versus 108–111), the midbody scale rows (37–41 versus 35–36), the total strigae on ten scales (84–105 versus 73– 83), the relative prefrontal width (3.26–4.01 versus 4.03–4.58), the relative longest finger length (2.43–2.95 versus 4.08–5.35), the relative frontal width (84.8–114 versus 73.6–81.9), and the relative distance between the eye and naris (3.10–3.67 versus 3.68–5.01). From W. orosaura sp. nov., we distinguish W. mylica by the adult SVL (76.0– 98.2 versus 59.6–68.0), the relative length of digits on one hindlimb (9.62–15.5 versus 18.6–19.7), the relative eye length (2.13–2.97 versus 3.04–3.56), the relative forelimb length (10.5–14.3 versus 16.9–17.2), the relative longest finger length (2.43–2.95 versus 3.86–4.46), and the relative frontal width (84.8–114 versus 80.0–84.6). From W. surda , we distinguish W. mylica by the relative width of canthal iii (0.956–1.15 versus 1.17–1.33).

Description of holotype. MCZ R-77049. An adult male; SVL 85.3 mm; tail nearly cylindrical, 100 mm (117% SVL); axilla-to-groin distance 53.6 mm (62.8% SVL); forelimb length 11.0 mm (12.9% SVL); hindlimb length 17.2 mm (20.2% SVL); head width 11.8 mm (13.8% SVL); diameter of orbit 2.39 mm (2.80% SVL); horizontal diameter of ear opening 0.00 mm (0.00% SVL); vertical diameter of ear opening 0.00 mm (0.00% SVL); length of all toes on one foot 10.8 mm (12.7% SVL); shortest distance between angled subocular and lip 0.43 mm (0.504% SVL); longest finger length 2.33 mm (2.73% SVL); largest supraocular width 2.53 mm (2.97% SVL); cloacal width 6.03 mm (7.07% SVL); mental width 1.66 mm (1.95% SVL); postmental width 2.48 mm (2.91% SVL); prefrontal width 3.42 mm (4.01% SVL); frontal width 114% frontal length; nasal height 0.96 mm (1.13% SVL); angled subocular height 1.28 mm (1.50% SVL); shortest distance between the eye and naris 3.00 mm (3.52% SVL); canthal iii width 0.83 mm (0.973% SVL); angled subocular width 1.95 mm (2.29% SVL); nasal width 1.41 mm (1.65% SVL); rostral 1.91X 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, and the frontal; frontal approximately as long as 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)/1 st and 2 nd temporals and frontoparietal (irregular) (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 supralabials (left)/(right); 2 nd loreal shorter than 1 st, higher than 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); 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)/5 (right) lateral oculars; 5 (left)/7 (right) temporals; 2 suboculars (left)/ (right); posterior subocular large and elongate (left)/(right); anterior subocular small (left)/(right); 9 supralabials (left)/(right), 5 to level below center of eye (left)/(right); 9 (left)/10 (right) infralabials, 6 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 1–3 scales; 107 transverse rows of dorsal scales from interoccipital to base of tail; 113 transverse rows of ventral scales from mental to vent; 39 scales around midbody; 4 digits; finger lengths 3>2>1>4; 6 (left)/7 (right) lamellae under longest finger; 23 total lamellae on one hand; toe lengths 3>2>4>1; 12 (left) lamellae under longest toe; keelless and striate dorsal body and caudal scales; smooth ventral scales; 105 total strigae counted on ten scales.

Color (in alcohol): dorsal surface of head dark gold with darker brown mottling and darker brown areas on scale borders; lateral surfaces of head grading from dark gold to faded dark brown with some cream spots on the sides of the throat and dark brown eye masks; dorsal surfaces of the body are medium brown with two darker brown longitudinal paramedian lines that end before the forearms in addition to many small, dark brown, irregular spots; dorsal surface of tail medium brown covered in small, dark brown, irregular spots; lateral areas grade from dark brown to dark cream with off-white mottling; dorsal surfaces of the limbs are dark brown with some paler cream spotting; lateral and ventral areas of the limbs fade to pale cream with heavy, dark brown spotting; ventral surfaces of the head, body, and tail are cream with heavy dark brown spotting that becomes the dominant color on the underside of the tail.

Variation. The majority of the examined material resembles the holotype in having irregular dots or flecks on their dorsum whereas a minority of specimens lack a pattern on their dorsum other than longitudinal paramedian markings. Several specimens have patternless heads whereas a majority possess darker outlines on their head scale borders and/or irregular darker markings on their head scales. AMNH 92087 and AMNH 92088 lack longitudinal paramedian markings whereas the markings in other specimens range from dots in series to small or broken lines to multiple thin lines. The dots in the lateral band appear mottled, as opposed to arranged in bars. Measurements and other morphological data for the holotype and other examined material are presented in Table 1 .

Distribution. Wetmorena mylica is distributed on the eastern coast of the Sierra de Baoruco in the Dominican Republic at elevations of 40–1390 m (Fig. 95). It has an extent of occurrence of extent of occurrence of ~ 520 km 2.

Ecology and conservation. No ecological data are associated with this species. We consider the conservation status of Wetmorena mylica to be Endangered B1ab(iii), based on IUCN Redlist criteria ( IUCN 2023). It faces a primary threat from habitat destruction resulting from agriculture and urbanization. Secondary threats to this species include predation from introduced predators, including the mongoose and black rats. Studies are needed to determine the health of any remaining populations and threats to the survival of the species.

Reproduction. A litter size of four was recorded in this species (SBH, field data).

Etymology. The species name ( mylica ) is derived from the Greek mylikos (mill), in reference to the type locality (an abandoned mahogany sawmill).

Remarks. Previously regarded as a subspecies of Wetmorena haetiana , herein we recognize W. mylica as a full species based on genetic and morphological differences. This species occurs at much lower elevations than other species (e.g., W. haetiana and W. surda ). Schwartz (1965) suggested that extreme deforestation in the other areas is the reason, whereas some lower-elevation habitat of W. mylica is still intact.

Although Wetmorena mylica and W. haetiana differ only in ventral coloration, they are not closest relatives, are genetically distinct from one another (Fig. 3), and have been diverged for 5.57 My (Fig. 4).

Wetmorena mylica was included in our genetic dataset and has significant support in both Bayesian and ML analyses at the crown node. The stem node that places W. mylica within Wetmorena has a support value of 65% in our ML analysis and is not supported in our Bayesian analysis. Schools et al. (2022) used genomic data to place W. mylica outside of W. haetiana and W. surda with significant support values in ML and Bayesian analyses. Based on our timetree (Fig. 4), Wetmorena mylica diverged from its closest relative 4.25 Ma, consistent with typical species of vertebrates (> 0.7 Ma; Hedges et al. 2015). Wetmorena mylica was recognized as a distinct species by our ASAP analysis.