Echinosaura, BOULENGER, 1890

ECHINOSAURA BOULENGER, 1890 View in CoL

Type species: Echinosaura horrida Boulenger, 1890 (by original designation).

Content: Seven species: Echinosaura brachycephala Köhler et al., 2004 ; E. centralis Dunn, 1944 ; E. horrida Boulenger, 1890 ; E. keyi ( Fritts & Smith, 1969) ; E. orcesi Fritts, Almendáriz & Samec, 2002 ; E. palmeri Boulenger, 1911 ; E. panamensis Barbour, 1924 .

Diagnosis: Phenotypic characteristics of Echinosaura include: (1) dorsal scales heterogeneous, with small or granular, irregular scales intermixed with tubercular or spine-like scales; (2) dorsal surface of the head with large, symmetrical and paired scales anteriorly, and with irregular small scales posteriorly; (3) internasal single or divided; (4) frontonasals paired; (5) prefrontals usually absent; (6) frontal scale single or divided; (7) frontoparietals small, paired; (8) interparietal and postparietal scales not well defined ( Fig. 10); (9) postmental large, single (reduced or absent in E. brachycephala ); (10) chin shields usually large, in one pair (smaller in E. horrida , not differentiated in E. brachycephala ) ( Fig. 10); (11) lower eyelid developed, with a palpebral disc divided into several, unpigmented scales; (12) ventral scales squared (or rounded squares), not imbricated; (13) limbs pentadactyl, digits clawed; (14) males with well-developed femoral pores, females usually lacking them or having fewer femoral pores than males (if present, weakly developed or barely distinguishable). Morphological variation among species of Echinosaura is summarized in Table 2 and 3.

Echinosaura differs from other cercosaurines, except Centrosaura , Gelanesaurus , Neusticurus , Potamites and Rheosaurus , in having heterogeneous dorsal scalation. It differs from the other genera with heterogeneous dorsal scalation in having small or granular, irregular dorsal scales intermixed with tubercular or spine-like scales (vs. small irregular or granular dorsal scales intermixed with large or polygonal keeled scales), several irregular scales on the parietal region (vs. regular scales on parietal region) and usually one pair of large chin shields (vs. usually more than one pair of large chin shields). A comparison of Echinosaura and closely related and morphologically similar genera is given in Table 5 and Figure 9.

Etymology: Although not explicitly stated by Boulenger (1890), the name Echinosaura (gender feminine) is presumably formed from the Ancient Greek ἐχῖνος, echinos (hedgehog or urchin) and σαύρα, saura (lizard) – a spiny lizard.

Geographic distribution: All species of Echinosaura are trans-Andean, extending from western Panama to north-western Ecuador. Most species occur in lowlands, but some reach as high as c. 2200 m a.s.l.

Remarks: Our phylogenetic analysis corroborated the inclusion of the previously not-analysed species E. palmeri and E. panamensis in Echinosaura s.s., as recently hypothesized by Torres-Carvajal et al. (2016).