Marisora magnacornae Hedges & Conn, 2012

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 : 333-334

Marisora magnacornae Hedges & Conn

Eastern Nicaraguan Skink

Fig. 12

Marisora magnacornae Hedges & Conn 2012:129 (holotype MCZ R26976; type locality “Great Corn Island, Nicaragua ”); Sunyer et al. 2013:1386; HerpetoNica 2015:220.

Marisora brachypoda : Hedges & Conn 2012:244 (in part).

Diagnosis. Marisora magnacornae is a long-limbed, relatively stout, large species of Marisora characterized (21 males, 14 females; marked with an * in specimens examined; data incomplete for some specimens) by (1) maximum known SVL 85.7 mm in males; (2) maximum known SVL 95.1 mm in females; (3) snout width 3.4–4.2% SVL in males, 2.6–4.1% in females; (4) HL 17.8–21.6% SVL in males, 16.4–20.9% in females; (5) HW 12.3–15.5% SVL in males, 11.0–14.8% in females; (6) EAL 1.3–2.3% SVL in males, 1.2–1.4% in females; (7) Toe IV length 10.9–13.3% SVL in males, 10.7–13.3% in females; (8) prefrontals one per side; (9) supraoculars four per side; (10) supraciliaries four per side; (11) frontoparietals one per side; (12) supralabial five below orbit on 53 sides, 6 on 9 sides; (13) nuchal rows one per side, except 1–2 in one (longitudinally divided by insertion of tiny scale for most of division); (14) dorsals 52–59 in males, 54–59 in females; (15) ventrals 57–65 in males, 57–62 in females; (16) dorsals + ventrals 109–122 in males, 111–121 in females; (17) midbody scale rows 30 in 27, 28 in 2; (18) Finger IV lamellae 12–15 per side in males, 11–15 in females; (19) Toe IV lamellae 15–18 per side in males, 15– 17 females [17]; (20) Finger IV + Toe IV lamellae 28–33 per side in males, 28–31 in females; (21) supranasals in medial contact in 31, not in contact in 1, preventing frontonasal-rostral contact in 96.9%; (22) prefrontals widely separated in 30, in contact with each other in 2; (23) supraocular 1-frontal contact absent in 26, present in 5; (24) parietals in contact posterior to interparietal; (25) pale middorsal stripe absent; (26) dark, thin dorsolateral dark stripe of dashes present in 15, absent in 18, pale brown to cream dorsolateral stripe present in 29 of 33; (27) dark lateral stripe present, about 2 scale rows high; (28) each side of body with distinct white lateral stripe; (29) palms and soles cream to dark brown; (30) total lamellae for five fingers 47–55 in males, 44–54 in females; (31) total lamellae for five toes 56–66 in males, 54–62 in females. In addition, this is a long limbed species with a combined FLL + HLL/SVL 60.8–68.7% in males, 55.8–68.0% in females, and usually has 2 chinshields contacting infralabials ( Table 3 ).

Marisora magnacornae is apparently a member of the M. alliacea Group of Middle American Marisora (no genetic data available). Marisora magnacornae has been diagnosed from the four species of Marisora described herein ( M. lineola , M. aquilonaria , M. syntoma , and M. urtica ) in their respective diagnoses above. Marisora magnacornae differs from the more southern and also Caribbean lowland M. alliacea in having 30 scales around midbody in 93.1% and 28 in 6.9% (versus 28 in 48.5%, 26 in 40.0%, or rarely 27 or 29 midbody scales in M. alliacea ) and having the fifth supralabial below the orbit in 85.5% (versus sixth supralabial below orbit in 73.8% of M. alliacea ). Marisora magnacornae is distinguished from the slightly more northern Caribbean M. roatanae in having longer limbs (FLL + HLL/SVL 60.8–68.7% in males, 55.8–68.0% in females versus 53.5–58.4% in males and 47.8–57.7% in females in M. roatanae ). Marisora magnacornae differs from M. brachypoda by having longer limbs (FLL + HLL/SVL 60.8–68.7% in males and 55.8–68.0% in females versus FLL + HLL/SVL 51.5–57.7% in males and 47.6–53.9% in females and in having a pale brown dorsolateral stripe (versus distinct pale brown dorsolateral stripe absent in M. brachypoda ). Marisora magnacornae differs from the extralimital M. pergravis by having fewer ventrals (57–65 in males versus 70–73 in M. pergravis ), fewer dorsals (52–59 versus 62–63 in M. pergravis ). Marisora magnacornae differs from M. unimarginata of the M. unimarginata group by having the fifth supralabial below the orbit in 85.5% (versus sixth supralabial below orbit in 81.9% in M. unimarginata ), 2 chinshields in con- tact with infralabials in 87.3% (versus 1 chinshield contacting an infralabial in 82.9% in M. unimarginata ), and having only scattered and slightly darker brown dorsal spots (versus numerous dark brown dorsal spots present in M. unimarginata ). Marisora magnacornae is known to differ from the extralimital and poorly known M. berengerae (incomplete morphological data from literature available only from the unsexed holotype) of the M. unimarginata group only from genetic data; furthermore a large geographical hiatus inhabited by other species of Marisora occurs between those two species.

Distribution. Marisora magnacornae was described based on a single specimen from Big Corn Island, but is now better known from several mainland localities along the environs of the Río Escondido and tributaries, Atlántico Sur, Nicaragua ( Fig. 6 ). Those mainland localities lie to the north, west, and south of Bluefields and lie in the lowlands on the Caribbean versant in eastern and south-central Nicaragua (about 4 to about 100 m elevation).

Remarks. Barbour & Loveridge (1929) evasively reported a single specimen (MCZ R 26976) of Mabuya (= Marisora ) from one of the Corn Islands; those authors did not refer to either of the two Corn Islands. Subsequently, no publication ever associated the Corn Islands with any discussion of these mabuyid skinks until Hedges & Conn (2012) described the MCZ specimen as the new species Marisora magnacornae (including all of those references listed in the synonymy of this species by Hedges & Conn). No specimens of Marisora have been collected on the Corn Islands since that original specimen in 1927–1928 (see Sunyer et al. 2013). Those circumstances might suggest that the single Corn Island specimen could have been introduced to that island by a boat carrying cargo from the mainland port of Bluefields, from which this skink is now known to occur to the north, west, and south.

Marisora magnacornae might be most closely related to M. alliacea . Both species are similar in limb length and occur in mesic Caribbean lowland habitats. Unfortunately, genetic data for M. magnacornae remain unknown.

Images of Marisora magnacornae are in Hedges & Conn (2012).

Figures

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 12. Adult female (USNM 19872) of Marisora magnacornae (Atlántico Sur, Nicaragua) in preservative showing dorsolateral pattern, SVL 83.5 mm.