Marisora urtica, Mccranie & Matthews & Hedges, 2020

Mccranie, James R., Matthews, Amy J. & Hedges, S. Blair, 2020, A morphological and molecular revision of lizards of the genus Marisora Hedges & Conn (Squamata: Mabuyidae) from Central America and Mexico, with descriptions of four new species, Zootaxa 4763 (3), pp. 301-353 : 325-328

Marisora urtica sp. nov.

Fonseca Islands Skink

Fig. 9

Marisora brachypoda : McCranie 2015:370 (in part); McCranie & Gutsche 2016:45 (in part); McCranie 2018:339 (in part).

Holotype. USNM 589196 , an adult male from Playa de Exposición , on east-southeast side of Isla Exposición, Golfo de Fonseca, Valle, Honduras, 7 m elevation, 13°18.891’N, - 87°40.447’W, collected by Alexander Gutsche & James R. McCranie, 15 July 2010. Laboratory sample number SBH 269996.

Paratypes (3). HONDURAS— Valle: USNM 589197, adult male, Punta El Molina, north portion of Isla Exposición 13°19.826’N, - 87°40.485’W; USNM 589194–95, adult males, Isla Garrobo, 13°20.002’N, - 87°42.795’W, 30 m elevation, Golfo de Fonseca.

Diagnosis. Marisora urtica sp. nov. is a relatively large, short-limbed species of Marisora characterized (data from four males in type series; females not known) by (1) maximum known SVL 77.0 mm; (3) SW 3.1–4.4% SVL; (4) HL 16.6–18.4% SVL; (5) HW 10.0–13.3% SVL; (6) EAL 1.4–1.9% SVL; (7) Toe IV length 10.0–11.2% SVL; (8) prefrontals one per side; (9) supraoculars four per side; (10) supraciliaries four per side; (11) frontoparietals one per side; (12) fifth supralabial below orbit; (13) nuchal rows one per side; (14) dorsals 52–58 (54.5 ± 2.6); (15) ventrals 53–59 (56.3 ± 2.8); (16) dorsals + ventrals 106–117 (110.8 ± 4.6); (17) midbody scale rows 26 in one (25.0%), 28 in three (75.0%); (18) Finger IV lamellae 11–12 (11.8 ± 0.5) per side; (19) Toe IV lamellae 15–16 (15.8 ± 0.5) per side; (20) Finger IV + Toe IV lamellae 26–28 (27.0 ± 1.2) on one side; (21) supranasals in medial contact, thus frontonasal not in contact with rostral; (22) prefrontals not in contact; (23) supraocular 1-frontal contact absent; (24) parietals in contact posterior to interparietal; (25) pale middorsal stripe absent, but 3–4 brown dorsal stripes present, especially anteriorly on body; (26) dark and pale dorsolateral stripes absent; (27) dark brown lateral stripe present; (28) distinct pale lateral stripe present; (29) palms and soles cream to pale brown; (30) total lamellae for five fingers 42–46 (42.8 ± 2.2); (31) total lamellae for five toes 47–55 (51.8 ± 2.9). In addition, this is a short-limbed species with FLL + HLL/SVL 48.2–57.5% that has only one chinshield per side (100.0%) contacting the infralabials ( Table 3 ).

Marisora urtica sp. nov. is a member of the M. alliacea group of Middle American skinks and is most closely related to M. syntoma ( Fig. 3 ). Marisora urtica differs from M. syntoma in having one chinshield contacting an infralabial (versus two chinshields contacting infralabials in M. syntoma ), reaching a larger size (maximum SVL 77.0 mm in males [females unknown] versus 68.5 mm SVL in males of M. syntoma ), and by having 2–3 fairly distinct to indistinct brown dorsal lines, especially anteriorly (versus those lines absent, but occasionally small dark spots or dashes present in M. syntoma ). Marisora urtica differs from M. aquilonaria in having one chinshield contacting an infralabial (versus two chinshields contacting infralabials in M. aquilonaria ), is a larger species (maximum SVL 77.0 mm in males [females unknown] versus 68.6 mm SVL in M. aquilonaria ), by having 2–3 fairly distinct to indistinct dark brown dorsal lines, especially anteriorly (versus those lines absent, but occasionally small dark spots or dashes present in M. aquilonaria ), and in having 4 supraciliaries per side (versus 5 superciliaries in 81.3% in M. aquilonaria ). Marisora urtica differs from M. brachypoda by the combination of having fairly distinct to indistinct brown dorsal lines, especially anteriorly (versus those lines normally absent in M. brachypoda ) and having 1 chinshield contacting an infralabial in all (versus 2 chinshields contacting infralabials in 77.8% of M. brachypoda ). Marisora urtica is distinguished from M. lineola by lacking pale and dark dorsolateral stripes and having 1 chinshield contacting an infralabial (versus those pale and dark dorsolateral stripes usually present and 2–3 chinshields contacting infralabials in M. lineola ). Marisora urtica differs from M. roatanae in having cream to pale brown palms and soles (versus distinct dark brown to nearly black soles and palms almost always present in M. roatanae ) and having 26–28 scales around midbody (versus 30–32 in 76.7% in M. roatanae ). Marisora urtica differs from M. magnacornae in having shorter limbs (FLL + HLL/SVL 48.2–57.5% in males [females unknown] versus 60.8–68.7% in male M. magnacornae ), in lacking pale and dark brown dorsolateral stripes (those stripes present in M. magnacornae ), and having 1 chinshield contacting an infralabial (versus 2 chinshields contacting infralabials in M. magnacornae ). Marisora urtica is distinguished from M. alliacea by having shorter limbs (FLL + HLL/SVL 48.2–57.5% in males [females unknown] versus 62.5–74.6% in male M. alliacea ) and in having pale palms and soles (versus dark in M. alliacea ). Marisora urtica differs from the extralimital M. pergravis by having fewer ventrals (53–59 in males versus 70–73 in M. pergravis ), fewer dorsals (52–58 versus 62–63 in M. pergravis ). Marisora urtica would be confused with M. unimarginata of the M. unimarginata group of Marisora using the Pinto-Sánchez et al. (2015) taxonomy, but differs from that species in having shorter limbs in males [females unknown] (FLL + HLL/SVL 48.2–57.5% versus 56.9–66.9% in M. unimarginata ), having pale palms and soles (versus dark in M. unimarginata ), having fifth supralabial below the orbit (versus sixth in 81.9%), and having less male ventrals (53–59, x = 56.3 ± 2.8 versus 60–65, x = 63.0 ± 2.3 in M. unimarginata ). Marisora urtica is known to differ from the extralimital and poorly known M. berengerae (incomplete morphological data available only from the unsexed holotype) of the M. unimarginata group only from genetic data; furthermore a huge geographical hiatus inhabited by other species of Marisora occurs between those two species.

Description of the Holotype. An adult male ( Fig. 9 ) in a good state of preservation. Tail broken near base, but with a short, poorly developed regenerated portion. A ventral incision present on left side for liver extraction. SVL 77.0 mm; HL 12.8 mm; HW 9.0 mm; SW 2.4 mm; EAL 1.5 mm; ear opening laterally ovoid; Toe IV length 7.9 mm; toe lengths in descending order I<V<II<III<IV.

Head scalation. Rostral wider than high, contacting first supralabial, anterior nasal, and supranasals. Paired supranasals in contact medially, preventing frontonasal-rostral contact, each supranasal also contacting upper edge of anterior loreal. Frontonasal decagonal, about as wide as long, laterally in contact with anterior loreal. A pair of pentagonal prefrontals, separated medially, and in contact with frontonasal, anterior and posterior loreals, first supraciliary, frontal, and first and second supraoculars. Frontal heptagonal, in contact with second supraocular, with frontonasal, and with paired frontoparietals. Frontoparietals also in contact with supraoculars 2–4 and with parietals and interparietal. Interparietal tetragonal and lanceolate, separated from nuchals by parietals. Parietal eye indistinct externally. Parietals in contact with upper primary, secondary and tertiary temporal scales. Four supraoculars per side, second one largest. Four supraciliaries per side, second longest. Nostril in posterior third of nasal, forming nasal division. Postnasal bordered by frontonasal, supranasal, anterior loreal, and first supralabial. Anterior loreal squarish, posterior loreal with posterodorsal projection. One upper preocular and one lower preocular. Seven supralabials, the fifth the longest and located below orbit. Four small postoculars, considerably smaller than temporal scales. Three primary temporals, two secondary temporals, and two tertiary temporal scales. All temporal scales imbricate, smooth, cycloid, not distinctly delineated from scales on nape and side of neck. Eight infralabials. Mental scale wider than long, posterior margin straight. Postmental and one chinshield per side in contact with infralabials. Anterior chinshield paired, in contact medially. Second chinshield paired, separated medially by a slightly smaller, somewhat cycloid-shaped scale.

Body and limb scalation. One row of enlarged nuchal scale per side, in contact medially. Other scales on nape similar in size and shape to dorsals. Lateral neck scales slightly smaller than dorsolateral nape scales. Dorsal scales cycloid, imbricate, smooth, 58 in a longitudinal row. Axillary pit absent, but small scales present in that region. Ventral scales similar in size and shape to dorsals, 59 in a longitudinal row. Twenty-six scales around midbody. No distinct boundaries between dorsals, laterals, and ventrals. Scales on base of tail and limbs similar in shape to dorsals, but smaller on limbs. Palmar and plantar surfaces with small, slightly conical scales, subequal in size, and delineated by a surrounding region of slightly larger, flat scales. Subdigital lamellae smooth, single, 12 on Finger IV, 14 on Toe IV. Total subdigital lamellae on fingers I–V 43, total on toes I–V 53. Preanal scales slightly larger than ventrals, slightly wider and close to rectangular. No enlarged median subcaudal scales.

Pattern and coloration in preservative. Dorsal ground color dark brown with distinct dark brown longitudinal dashes or 3–4 incomplete lines, those lines more evident anteriorly. Pale and dark dorsolateral stripes or lines absent. Dark brown lateral stripe distinct, solid color, 3 scale rows high, extending from posterior edge of orbit to level above hind limb insertion. A single, relatively broad (ca. 2 scale rows high) white lateral stripe present per side, extending from rostral onto anterior portion of tail, not passing along upper edge of hind limb, passing across lower half of ear opening and with an equal height below ear opening. Scattered distinct dark brown spots present on medium brown dorsal surfaces of limbs. Indistinct dark brown ventrolateral stripe plus an indication of a single white ventrolateral line present on one side. Ventral surface of body cream, occasional darker brown spots present ventrolaterally. Palmer and plantar surfaces cream, same color as adjacent undersides of limbs. Adjacent lamellae a darker grayish-brown.

Variation. All paratypes are rather similar in color and pattern as that described for the holotype. Table 3 shows some of the more important variation recorded for measurements and proportions and some scale counts for the entire type series.

Distribution. Marisora urtica is known to occur on two islands in the western portion of the Golfo de Fonseca in the Pacific Ocean in southern-most Honduras ( Fig. 6 ; but see Remarks). Its known elevational distribution is from near sea level to about 30 m. The species has not been reported from any of those nearby islands in the Golfo de Fonseca belonging to El Salvador. Marisora urtica is replaced by M. brachypoda on three eastern-most Honduran islands in that gulf ( Fig. 6 ).

Ecology and conservation. McCranie & Gutsche (2016:874) discussed the general habitats of a combination of Marisora urtica and M. brachypoda on the Golfo de Fonseca islands. Those authors wrote that these skinks were “diurnal, terrestrial, or arboreal species that is highly adaptable and can be found in a variety of habitats, including edificarian situations. Although frequently active on the ground, it also climbs to bask on tree trunks, fence posts, brush piles, or other elevated objects.” As is the case with all Marisora species, no conservation studies have been published pertaining to this species, but other Middle American species adapt well to human presence, even living inside human inhabited houses (JRM pers. observ.). Thus, M. urtica is considered a species of little or no conservation concern (although see comments in account of M. lineola regarding the susceptibility of mabuyid skinks to invasive predators).

Reproduction. Nothing has been published on reproduction in Marisora urtica , and McCranie & Gutsche (2016) did not recover any reproductive information during their collections of this species. Species of Marisora are viviparous. Etymology. The specific name urtica , a noun in apposition, is Latin for nettle. The name is used in reference to the abundance of stinging nettles that at some places on Isla de Exposición seemed impossible to avoid contact with. The usage of urtica for this species name refers to the first author’s memories of those contacts with shrubs and small trees of those nettles while in pursuit of these fast moving skinks.

Remarks. Marisora urtica was recovered as a separate clade by our genetic analysis of tissues from the holotype (USNM 589196). As a result, close morphological examination of that tissue voucher specimen and three other adults of that and another nearby island population revealed supporting morphological characters to distinguish this species from the other members of the M. alliacea group. Our genetic results also recovered two subclades (four tissue sequences) from Pluma Hidalgo, Oaxaca, Mexico, that cluster with M. urtica . Unfortunately, and because of the poorly documented literature, we were unable to locate any museum specimens from Pluma Hidalgo to examine their morphology. As a result, we only tentatively include that Oaxaca population as M. urtica . Pluma Hidalgo lies about 90 km south-southwest of the nearest M. syntoma locality (southeast of Nejapa de Madero). Also, according to Binford (1989: his fold out map), Pluma Hidalgo lies in Tropical Semideciduous Forest, whereas the remaining Oaxaca localities (= M. syntoma ) for this skink complex are in Tropical Deciduous Forest.

No images of Marisora urtica have been previously published.

Figures

FIGURE 3A. Phylogenetic tree of the genus Marisora from a maximum-likelihood analysis of DNA sequences of three mitochondrial genes (12S rRNA, 16S rRNA, and cyt b) and three nuclear genes (NGFB, R35, and RAG2) in 140 individuals (4,029 bp). A scale bar (2% sequence divergence) is indicated below. The numbers at left of nodes are bootstrap support values. The tree is rooted with Mabuya dominicana. Species delimited using ABGD indicated by black vertical lines at right; samples with horizontal bars missing cytochrome b Figure continues on two pages.

FIGURE 6. Map showing the localities of the Marisora specimens examined for this study. The gray arrow points to island record for M. urtica. Two extralimital species are also indicated: M. berengerae (San Andres, purple arrow) and M. pergravis (Providencia, yellow arrow).

FIGURE 9. Adult male holotype (USNM 589196) of Marisora urtica (Isla Exposición, Valle, Honduras) in preservative showing indistinct lines on anterior portion of body, HL 12.8 mm, SVL 77.0 mm.