Scriptosaura catimbau, Rodrigues, Miguel Trefaut & Santos, Ednilza Maranhão Dos, 2008

Rodrigues, Miguel Trefaut & Santos, Ednilza Maranhão Dos, 2008, A new genus and species of eyelid-less and limb reduced gymnophthalmid lizard from northeastern Brazil (Squamata, Gymnophthalmidae), Zootaxa 1873, pp. 50-60 : 52-57

Scriptosaura catimbau , sp. nov.

( Figs. 1 , 2 , 3 )

Holotype: MZUSP 98059, an adult male from Fazenda Porto Seguro (08o29’13’’S, 37o16’52’’W), municipality of Buíque, Parque Nacional do Catimbau : State of Pernambuco: Brazil; collected on 7th March 2008 by Miguel T. Rodrigues and Ednilza Maranhão dos Santos, field number MTR 15401.

Paratypes: Males: MZUSP 98060, 98061, 98063, 98065, 98068–71, 98075, 98076; females: MZUSP 98062, 98064, 98066, 98067, 98072–4; collected between 7–8th March 2008 by Miguel T. Rodrigues and Ednilza Maranhão dos Santos; all other data as for the holotype.

Etymology: A noun in apposition, in reference to the type locality, Parque Nacional do Catimbau .

Diagnosis: A small elongate gymnophthalmid (maximum SVL 53 mm) with a prominent snout and body slightly longer than tail. Forelimbs absent, hindlimbs rudimentary, styliform, ending in a small apical scale. Ear opening and eyelid absent. Frontonasal single, contacting parietal; prefrontals, frontal, frontoparietals, supraoculars, and loreal absent. Parietals longer than wide. Nostril in the center of nasal. Two supraciliaries, the anterior one larger, diagonally disposed, contacting subocular. Collar fold absent. One pair of chin shields. Dorsal scales cycloid, smooth anteriorly, posteriorly hexagonal, keeled, in 39–41 regular transverse series; lateral scales enlarged, smooth. Ventral scales smooth, in 32–34 transverse rows and four regular longitudinal series, the external ones wider; 15–19 scales around body. Males with four preanal pores, absent in females.

Description of the holotype ( Figs. 1 , 2 ): Body long, snout prominent, without pronounced constrictions in neck or base of tail; no evidence of collar fold. Rostral broad, broadly projecting over symphysial; slightly wider than high, contacting first supralabial, nasal and frontonasal. In lateral view, the rostral forms an acute angle, with about 3/4 of its total length visible from above, the other quarter extends straight ventrally, in the same plane with the symphysial. Frontonasal hexagonal, longer than wide, reaching the level of posterior margin of the eye, wider posteriorly, in contact with rostral, nasal, first and second supraciliaries, parietal, and interparietal. Sutures with rostral and interparietal, broad and straight, that of first supraciliary concave, and those of second superciliary and parietal smaller. Prefrontals, frontals, supraoculars, and frontoparietals absent. Interparietal about twice as long as wide, as long as frontonasal and slightly longer than parietals; wider and straight anteriorly, posteriorly rounded; its lateral margins straight, converging posteriorly; separated from second supraciliary by parietal-frontonasal contact. Parietals irregularly hexagonal, longer than wide, contacting frontonasal, second supraciliary, a small postocular granule, an enlarged postocular, an enlarged elongate temporal, interparietal, and first dorsal row. A diagonally directed, postero-anterior oriented and polygonal supraciliary is longer than wide; anteriorly wider and contacting nasal, second supralabial, subocular, frontonasal and second supraciliary; longest suture with frontonasal. Second supraciliary small, contacting first supraciliary, frontonasal, parietal, and a small postocular. Subocular mostly above third supralabial, longer than wide, smaller than first supraciliary, contacting first supraciliary anteriorly and an enlarged postocular posteriorly which separates parietal and fourth supralabial. Eye small, as large as second supralabial, inserted between subocular, supraciliaries and three small postocular granules. Eyelids absent; eyeball round. Nasal pentagonal, above first and second supralabials, longer than wide, wider anteriorly, contacting additionally rostral, frontonasal and first supraciliary; nostril in center of nasal. Loreal and frenocular absent, probably fused with first supraciliary and corresponding to its wider portion. Five supralabials in the following order of increasing size of their base: first, fourth, second, third, and fifth; third below eye, fourth the highest. A longer than wide diagonally disposed temporal above fourth and fifth supralabials followed posteriorly by a series of dorso-ventrally oriented and imbricate higher than wide scales which cover tympanum; external ear opening absent.

Symphysial broad, with convex anterior border and straight posterior margin, slightly wider than long, contacting first infralabial and postmental, and situated clearly posterior to ventral edge of rostral. Postmental single, roughly pentagonal, longer than wide, contacting first and second infralabials. A single pair of genials in broad contact at midline and contacting second and third infralabials. Four infralabials, first the smallest, second and third the largest and with the same approximate size. All head scales smooth and juxtaposed, with irregularly distributed small sensorial organs. Two longitudinal series of transversally enlarged gular scales, smooth, imbricate, disposed in seven rows and extending from genials to the interbrachial region. Gular scales separated from lateral neck scales by a series of much smaller and longitudinally elongated and diagonally disposed scales. Interbrachial region with four longer than wide transversally disposed scales, the central ones larger. Ventrals in four longitudinal rows, the external one larger, the others longer than wide, imbricate, smooth, quadrangular; 33 transverse rows between gulars and preanal region.

Anterior dorsal scales cycloid, smooth and imbricate, wider than long or irregular in size, becoming longer than wide and rounded posteriorly at the level of fifth row and then progressively changing to hexagonal, slightly keeled and mucronate until the level of leg insertion; 40 regularly transverse rows between interparietal and posterior level of leg insertion; 19 scales around midbody. Lateral neck scales smooth, cycloid, imbricate; the uppermost rows being larger and higher than long; other lateral neck scales smaller, irregular in size and shape and disposed in two irregularly longitudinal rows. Flanks with a ventrolateral row of smooth, imbricate and elongate scales with approximately the same size as dorsals. Above it, two irregularly longitudinal rows of subrectangular enlarged scales.

Preanal region with four scales ( Fig. 2 ), the two lateral ones larger than and separated on the midline by centrals, which are longitudinally in contact. Four preanal pores. Dorsal part of tail with slightly smaller scales than posterior dorsals but keeled and strongly imbricate. Other parts of tail identical to their corresponding parts of the body. Differences between dorsal, lateral, and ventral scales of tail disappear gradually towards tip of tail.

Forelimbs absent. Hindlimbs reduced to a needle-shape vestigial leg bud covered by five scales from the base to the tip; nail absent.

Dorsal surface of body and tail light brown with a regular series of transverse darker dots corresponding to the posterior part of dorsal scales. A wide lateral dark brown stripe, formed by a highly irregular reticulate pattern and decreasing ventrally in conspicuity, extends along head, body, and tail from nasal to tip of tail. Ventral parts of head and gular region cream with an irregular dark brown reticulum. Ventral parts of body cream with a transverse series of dark brown dots, larger than dorsal ones. Tail color identical to body except ventrally where occasionally there are some dark spots, all the rest immaculate. Limb buds light brown dorsally with a reticulate pattern identical to that of lateral stripe; ventrally immaculate.

Measurements of the holotype: snout-vent length 45 mm; tail 19 mm (broken); diameter at midbody 4,2 mm; right leg bud 2,2 mm.

Variation: Males are slightly smaller and have slightly longer tails than females: maximum SVL for males and females were 48 mm and 53 mm, respectively. SVL varied respectively in males and females from 1.04 to 1.15 and 1.06 to 1.36 times tail length (r 2 males 0.99, n = 4; r 2 females 0.84, n = 4). No sexual differences were found in squamation. Variation in meristic characters (n = 19) was the following (mean and standard deviation, respectively, in parenthesis): dorsal rows, 39–41 (40.1 ± 0.65); ventrals 32–34 (33 ± 0.66); scales around midbody 15–19 (17.7 ± 1.04). Like the holotype, all specimens have two supraciliaries and one subocular, except for MZUSP 98074, with two suboculars. Likewise all the specimens have five supralabials, four infralabials, and seven gular rows, except for MZUSP 98075 which has eight. Four preanal pores are present in all males examined; they are absent in females. The styliform hindlimb is covered by five scales in all specimens. The color pattern of males and females is very similar except in adult males where ventral surfaces are characteristically reticulated with dark brown whereas in adult females and juveniles ventral surfaces are immaculate.

Distribution and natural history: The Parque Nacional do Catimbau ( Fig. 4 ) was recently created to protect the habitats included in or surrounding the highly eroded plateau of Silurian-Devonian sedimentary deposits of Tacaratu formation ( Projeto RADAMBRASIL 1983; CPRM 2005) in the Caatingas of State of Pernambuco. The area, with about 62,000 hectares, consists of extensive arenitic and conglomerate outcrops of the plateau and areas of accumulation of sandy soils resulting from its erosion ( RADAMBRASIL 1983). Sandstones are irregularly capped with conglomerates which gives some protection from erosion. The plateau, with elevations varying between 700 and about 1000 m, is highly dissected at the borders ( Fig. 5 A) and predominantly covered by a xeromorphic Caatinga vegetation. Plant families dominant in the area are the Euphorbiaceae , Caesalpiniaceae , Myrtaceae , Mymosaceae, Fabaceae and Cactaceae ( Gomes et al. 2006) . Although less abundant, the Bromeliaceae are also characteristic either in the outcrops or in the sandy soils; in the latter habitat the caroá ( Neoglaziovia sp.) is particularly frequent ( Fig. 5 B). On sandy areas vegetation cover consists basically of scattered thickets of variable size with a dry, and thin leaf litter generally concentrated at the basis of trees and bushes and separated by spaces of bare sand ( Fig. 5 B). At some places near the lower slopes of the highly eroded plateau where water is more abundant vegetation is higher and evergreen, and a denser and humid leaf litter is present. Annual mean temperatures and precipitation in the area are 26o C and 600 mm, respectively; most of the rain falls between April and June ( Nimer 1979; Gomes et al. 2006).

All specimens of Scriptosaura catimbau were found on the slopes of the northern border of the plateau, while searching among the leaf litter around vegetation thickets in the sandy areas. They were always found buried in the sand a few centimeters below surface. When exposed they always tried to escape with fast sand swimming movements below sand. Although we obtained only 19 specimens, several escaped; the characteristic tracks left in the sand ( Fig. 5 C) suggest that the species is very abundant in the area. The presence of recent tracks during the day in areas previously searched for specimens and where tracks had been absent suggest diurnality. The presence of several small juveniles in our sample indicates their recent eclosion. Other lizards obtained in the area were the tropidurids Tropidurus cocorobensis , Tropidurus hispidus , and Tropidurus semitaeniatus , the iguanid Iguana iguana, the gymnophthalmids Acratosaura mentalis , Anotosaura vanzolinia , Micrablepharus maximiliani , and Vanzosaura rubricauda , the teiids Ameiva ameiva, Cnemidophorus ocellifer and Tupinambis merianae , the gekkonids Hemidactylus brasilianus , Phyllopezus pollicaris , and Phyllopezus periosus , and the scincid Mabuya agmosticha .

Figures

FIGURE 1. Lateral, ventral, and dorsal views of the head of the holotype of Scriptosaura catimbau (MZUSP 98059).

FIGURE 2. Ventral view of the hindlimbs and preanal region, and a schematic view of the midbody scalation of the holotype of Scriptosaura catimbau (MZUSP 98059).

FIGURE 3. Living specimen of Scriptosaura catimbau from Parque Nacional do Catimbau.

FIGURE 4. Type locality of Scriptosaura catimbau in the context of the Caatingas of northeastern Brazil (gray) and that of Parque Nacional do Catimbau.

FIGURE 5. General aspect of the eroded border of the sandstone Silurian Devonian plateau at Parque Nacional do Catimbau, type locality of Scriptosaura catimbau (A); typical sandy habitat of Scriptosaura catimbau, note the abundance of the “ caroá ” (Neoglaziovia sp.), the thin bromeliad (B); track of Scriptosaura catimbau (C).