Caparaonia, Rodrigues & Cassimiro & Pavan & Curcio & Verdade & Pellegrino, 2009

Rodrigues, Miguel Trefaut, Cassimiro, José, Pavan, Dante, Curcio, Felipe Franco, Verdade, Vanessa Kruth & Pellegrino, Kátia Cristina Machado, 2009, A New Genus of Microteiid Lizard from the Caparaó Mountains, Southeastern Brazil, with a Discussion of Relationships among Gymnophthalminae (Squamata), American Museum Novitates 3673, pp. 1-28 : 4-6

Caparaonia , new genus

DEFINITION: An elongate gymnophthalmid (maximum SVL 60 mm) with distinctive ear opening and eyelid, long tail (1.5–2.5 times SVL), and slender pentadactyl limbs (fig. 1); first toe lacking claw. Frontonasal single; prefrontals, frontoparietals, parietals, interparietal, and a pair of occipitals present. Parietals longer than wide. Collar fold absent. Three pairs of chin shields and three supraoculars. Dorsal and lateral scales lanceolate, strongly keeled, with sides of scales almost juxtaposed. Ventrals longer than wide, smooth, in six regular transverse rows, the lateral ones narrower. Males with a continuous series of pores without gap between preanal and femoral ones; 2–5 inconspicuous preanal pores in females. Hemipenis not totally everted, with a series of naked W-shaped and continuous transverse flounces ending in bifurcate end-free protuberances as wide as and continuous with the flounces; sulcus spermaticus apparently single, edged by an extensive naked area.

CONTENT: Caparaonia itaiquara , new species, monotypic.

ETYMOLOGY: Named for the Caparaó mountains, the type locality, and meaning ‘‘from Caparaó.’’

COMPARISONS: Most character states for the taxa compared here are summarized in appendix 2. The Heterodactylini consists of two strongly supported groups of genera: the Heterodactylus – Colobodactylus clade and all the other Heterodactylini [ Alexandresaurus , Acratosaura , Colobosaura , Iphisa , and Stenolepis ] ( Rodrigues et al., 2007). In addition to molecular characters, the two assemblages are supported by the condition of the supratemporal fenestra, the lateral expansion of the parietals, the postorbital width, the shape of the postfrontal, and the shape and size of the parietal scale ( Rodrigues et al., 2007). The assemblage Colobodactylus – Heterodactylus also differs from the remaining Heterodactylini by their more elongated body and higher degree of limb reduction.

The following characters place Caparaonia squarely among the Heterodactylini : interclavicle cross shaped, with a central area extremely reduced; lateral process of interclavicle long, straight, and pointed; glossohyal fused to basihyal; nasals in slight contact with premaxilla, wide, divergent, and in contact at midline but broadly separated anteriorly by the subtriangular lamina of the premaxillary ( Rodrigues et al., 2007).

The presence of an opened supratemporal fenestra, a narrow postorbital covering the postfrontal, and the absence of lateral expansion on parietal bones associate Caparaonia with the Colobodactylus – Heterodactylus assemblage. Another possible character linking Caparaonia to Colobodactylus and Heterodactylus is the condition of the parietals. These scales are wider than long in Colobodactylus and Heterodactylus whereas they are longer than wide in all other Heterodactylini . As previously reported this difference is probably due to a scale rearrangement in Heterodactylus and Colobodactylus in which parietals (and the interparietal in Colobodactylus ) are divided and their posterior regions incorporated into the highly conspicuous occipitals that characterize both genera ( Rodrigues et al., 2005). The parietals of Caparaonia are not so reduced as those of Colobodactylus and Heterodactylus , but they are certainly shorter than those of other Heterodactylini . This suggests that although the parietals of Caparaonia may not be strictly homologous with those of Colobodactylus or Heterodactylus , they are strikingly different from the other genera of the tribe.

Caparaonia differs from Colobodactylus and Heterodactylus (data for the latter genera in parenthesis) by having a distinctive first finger (absent), distinctive prefrontal scales (absent), three pairs of chin shields (two pairs), and by having naked W-shaped flounces terminating by bifurcate free-ending extremities in the hemipenis (only V-shaped naked flounces). Caparaonia further differs from Colobodactylus by having ventral scales longer than wide (wider than long) disposed in 6 longitudinal rows (4), the lateralmost being the narrowest (the wider), and from Heterodactylus by the presence of an interparietal (absent or extremely reduced), by presenting a distinctive ear opening (absent), and a slightly elongate body (extremely elongate). From the other Heterodactylini Caparaonia differs by having no spines and naked W flounces on the hemipenis (spines present and flounces with conspicuous combs of spines). Caparaonia differs from Iphisa by having three pairs of genials (one pair), several rows of lanceolate and keeled dorsal scales (only two longitudinal smooth scale rows), ventral scales longer than wide, regularly transverse and in six longitudinal rows (not in transverse rows and in only two very enlarged longitudinal rows), and regularly transverse rows of mostly small gulars irregularly disposed in longitudinal rows (gulars very enlarged in only two rows neither regularly transverse or longitudinal). From Colobosaura , Acratosaura , Stenolepis , and Alexandresaurus , it can be distinguished by having six longitudinal and regularly transverse rows of laterally juxtaposed ventral scales that are longer than wide (four rows of imbricate quadrangular ventral scales, not regularly transverse). It additionally differs from Stenolepis by presenting prefrontals (absent), and by having small dorsal neck scales (large, in 3–4 longitudinal rows) and from Stenolepis , Alexandresaurus , and Colobosaura by having three pairs of genials (two pairs).

Finally, although the hemipenes are not totally everted and we lack data from Stenolepis , some differences are apparent. The flounces of the hemipenis of Caparaonia , Colobodactylus , and Heterodactylus are continuous, but in Alexandresaurus , Acratosaura , Colobosaura , and Iphisa the flounces are interrupted by a naked area on the side of organ opposite to the sulcus as well as medially on the right and left side.

Caparaonia further differs from all other Gymnophthalmini except Tretioscincus by the presence of a distinctive eyelid. Tretioscincus , like all other Gymnophthalminae, have characteristic skinklike scales, which are absent in Caparaonia .