Microlophus arenarius (TSCHUDI, 1845)
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Microlophus arenarius
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| Higher Taxa | Tropiduridae, Iguania, Sauria, Squamata (lizards) |
| Subspecies | |
| Common Names | |
| Synonym | Steironotus (Eulophus) arenarius TSCHUDI 1845: 154 Tropidurus stolzmanni STEINDACHNER 1891: 376 Tropidurus tschudii ROUX 1907 Tropidurus occipitalis stolzmanni — MERTENS 1956 Ophryoessoides arenarius — ETHERIDGE 1966 Steironotus arenarius — FRITTS 1974: 51 Tropidurus arenarius — FRITTS 1974: 69 Tropidurus stolzmanni — DIXON & WRIGHT 1975: 34 Microlophus stolzmanni — FROST 1992 Tropidurus occipitalis stolzmanni — TIEDEMANN et al. 1994 Tropidurus arenarius — LEHR 2002: 203 Stenocercus arenarius — TORRES-CARVAJAL 2004 Microlophus stolzmanni — TORRES-CARVAJAL 2004 Tropidurus arenarius — TORRES-CARVAJAL 2005 (pers. comm.) Microlophus arenarius — CARVALHO 2021 |
| Distribution | Peru Type locality: Huacho, north of Lima, Peru. stolzmanni: N Peru; Type locality: “bei Chota” |
| Reproduction | oviparous; <br />stolzmanni: Females from 65 to 76 mm in snout-vent length contained 3 to 4 oviducal eggs. All oviducal eggs examined were shelled and apparently ready for deposition. One female 73 mm in snout-vent length contained 16 unyolked ovarian eggs. These lizards were taken between 23-28 November 1969 [DIXON & WRIGHT 1975]. |
| Types | Lectotype: MHNN 2275, designated by Carvalho 2021; the lectotype designated by Ortiz 1989 (NHMB 6035) is actually Stenocercus formosus, fide Carvalho, pers. comm., 11 July 2023. Syntypes: NMW 18908: 1, 2 [stolzmanni] |
| Diagnosis | Diagnosis: Tropidurus stolzmanni is a member of the occipitalis group and differs from the other members of the group by lacking middorsal spots and by having chevron-shaped lines in the gular region, more prominent in males; differing also from occipitalis in lacking an occipital spot. Adult males of stolzmanni differ from males of both koepckeorum and occipitalis in having a broad, black-bordered, white stripe from the eye to near midbody [DIXON & WRIGHT 1975]. Fritts 1974: 52 provides a summary of characters of S. arenarius Description (arenarius lectotype): “Adult male, body and limbs robust, SVL 120.15 mm; head triangular, length 28% of SVL and width 68% of head length; skull not compressed medially, not elevated at level of the orbits; scales of frontonasal region slightly tumescent, not imbricate posteriorly; rostral about three times as high as first supralabial in lateral view, not tumescent, contacting first supralabials, first lorilabials, right nasal, and three postrostrals; 2/1 postrostrals; nasal single, slightly higher than adjacent scales, separated from rostral by postrostral only on the left side; 6/6 enlarged supralabials followed by 4/3 smaller scales reaching the rictus oris, never contacting subocular; nostril oval/sub-reniform, occupying about 40% of nasal, positioned posteriorly, directed dorsolaterally, borders elevated posteriorly; 3/3 canthals; 5/6 enlarged, laminate superciliary scales; 1/1 dorsally keeled, subrectangular preoculars contacting 2/3 loreals; 1/1 dorsally keeled, elongate suboculars, separated from supralabials by lorilabials; palpebrals granular, second row formed by slightly tumescent, subconical scales, bearing a scale organ on top; 4/4 rows of supraoculars, anterior ones occupying less than one third of the width of the supraocular area, enlarged supraoculars occupying more than one third of the width of the supraocular area; 2/2 rows of angulate circumorbitals, smaller or about the same size of anteriormost supraocular scales; 1/1 rows of squarish or polygonal scales separating supraorbitals from superciliaries; 1/1 rows of short, laminate scales separating superciliaries from palpebrals likely present but not easily observable because ocular region is partially depressed due to wilting of the eyes; interparietal enlarged, several times larger than adjacent parietals and occipito‐parietals, squarish, slightly depressed antero‐medially; parietal eye not visible; one enlarged parietal on each side of interparietal, about 25% the size of interparietal; occipito‐parietals angulate, tumescent, subconical, slightly imbricate posteriorly, noticeably smaller than parietals; temporals keeled, slightly imbricate, about the same size or slightly smaller than occipito‐parietals and larger than lateral neck scales; two rows of occipitals separating interparietal from dorsals; ear with shape of inverted keyhole, canal noticeably deep, largest diameter of ear opening about 20% of ear opening to snout distance; preauricular fringe formed by at least 7/6 enlarged scales; mental extending posteriorly to the level of the first third of the adjacent infralabials; 6/6 enlarged infralabials followed by 4/3 small scales reaching the rictus oris; 4/4 enlarged postmentals; postmentals not in contact with infralabials; first postmentals not contacting one another; 11/10 sublabials in contact with enlarged infralabials; 44 gulars, imbricate posteriorly. Vertebral crest present, tall, spine‐like scales extending through the tail (final third regenerated), vertebral spines relatively homogeneous in size; 60 vertebrals; 105 paravertebrals; 100 scale rows around midbody; 76 ventrals; dorsals large, keeled, imbricate, mucronate; scales on the armpit region small, smooth, non‐mucronate, growing in size and mucronation along the flanks; ventrals smooth, non‐mucronate, imbricate, slightly larger or about the same size as dorsals; supra‐carpals and supratarsals sub‐rhomboidal, anterior ones smooth, posterior ones keeled, some of them bearing a scale organ on the distal end of the scale; infra‐carpals keeled and infra‐tarsals smooth anteriorly and keeled towards fingers III and IV, mucronate; fingers and toes thin, cylindrical, slightly compressed laterally; supra‐digital lamellae subtriangular to sub‐rhomboidal, smooth; infra‐digital lamellae tricarinate, 23/23 under fourth finger, 30/32 under fourth toe, medial careen larger and more projected than lateral; ungual similar to subdigital lamellae; claws long or curved; preaxial scales of arm keeled, mucronate, grading into smooth scales on the ventral surface of the limb; preaxial and ventral scales of the leg smooth, slightly mucronate, post‐axial scales strongly keeled and mucronate, reducing in size towards the ventral surface; 28/28 tibial scales, keeled, strongly mucronate; dorsal body scales about the same size or slightly larger as scales on flanks, keeled, mucronate; rictal, nuchal and suprauricular folds absent; postauricular fold present, oblique neck fold well marked; antegular fold present, bearing a ventrolateral mite pocket on each side, coated with granular scales; gular fold present, incomplete medially, extending dorsally to form a well‐marked antehumeral fold; longitudinal fold present on the lateral body between post‐axillary region and midflank, supernumerary folds perpendicular to longitudinal fold present anteriorly, in the post‐axillary region; axillary and inguinal mite pockets absent; tail cylindrical, slightly compressed laterally; 56% of total length; caudal verticils absent; scales of tail up to three times larger than dorsals, imbricate, keeled, and mucronate dorsally, smooth and non‐mucronate ventrally; dorsal crest formed by serrate scales similar to those on dorsal body.” (Carvalho 2021: 43) |
| Comment | Synonymy: Carvalho 2021 synonymized stolzmanni with arenarius, although he did not examine the types. His conclusion is based on the description by Steindachner and others Habitat. The majority of specimens were found on or near small boulders, trees, and shrubs. Several were found under debris associated with abandoned human dwellings. Most were found in habitats with some kind of vegetation, such as mesquite, acacia, Capparis scabrida, dense beach shrubs or semiarid woodlands of the foothill slopes. This species is primarily scansorial; most specimens were taken one to three dm above the ground on trees. However, some were taken on the ground in the vicinity of shrubs where they appeared to be foraging for food [DIXON & WRIGHT 1975 on M. stolzmanni]. NCBI taxonID: 179259 [stolzmanni] |
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