Madascincus arenicola MIRALLES, KÖHLER, GLAW & VENCES, 2011
Can you confirm these amateur observations of Madascincus arenicola?
|Higher Taxa||Scincidae, Scincinae, Scincoidea, Sauria, Squamata (lizards)|
|Synonym||Madascincus arenicola MIRALLES, KÖHLER, GLAW & VENCES 2011|
|Distribution||N Madagascar (Antsiranana)|
Type locality: Baie des Sakalava (ca. 5 km SE Ramena), 12°16'34'' S, 49°23'24'' E, 25 m above sea level, Antsiranana Province, northern Madagascar
|Types||Holotype: ZSM 1565/2008 (field number FGZC 1703), adult male, collected on 20 February 2008 by S. Megson. Paratypes (8 specimens). ZSM 1564/2008 (FGZC 1922), Ampombofofo region (Frontier base camp), 12°05'53'' S, 49°19'49'' E, 28 m a.s.l., collected on 10 June 2006 by S. Megson; ZSM 2076/2007 (FGZC 1031), UADBA uncatalogued (FGZC 1029, 1030), Baie des Dunes (E Ramena), 12°14'43'' S, 49°22'53'' E, 14 m a.s.l., collected on 23 February 2007 by P. Bora, H. Enting, F. Glaw, A. Knoll and J. Köhler; ZSM 1566–1569/2008 (FGZC 1743, 1744, 1767, 1797), Baie des Sakalava (ca. 5 km SE Ramena), 12°16'34'' S, 49°23'24'' E, 25 m a.s.l., collected from 21 to 23 February 2008 by S. Megson. All localities within Antsiranana Province, northern Mada- gascar.|
|Diagnosis||Diagnosis. As a member of the Malagasy scincine lineage, Madascincus arenicola differs from the other Malagasy lygosomine genera (Cryptoblepharus and Trachylepis) by the presence of entirely scaly movable eyelids (versus fused immovable eyelids forming a spectacle over the eye in Cryptoblepharus; or movable eyelids with a translucent disk or window in the lower eyelid in Trachylepis), absence of prefrontal scales (present in both Cryp- toblepharus and Trachylepis), and absence of frontoparietal scales (present in Trachylepis).|
Within the Malagasy Scincinae, Madascincus arenicola is easily distinguishable from all other species by the combination of the following characters: presence of two pairs of pentadactyl legs, light bronze dorsal coloration with two dark well-defined lateral stripes, and absence of postnasals. The new species is assigned to the genus Madascincus based on its molecular phylogenetic relationships.
Within the genus Madascincus, the absence of postnasal scales is exclusively associated to M. arenicola. In addition to this highly discriminant character, M. arenicola is distinguished from all its congeners by the following combination of characters: SVL ranging from 61.5 to 81.7 mm (versus a maximum SVL of 29 mm in M. nanus, 33.5 mm in M. macrolepis, 39 mm in M. minutus, 50 mm in M. ankodabensis, 57 mm in M. melanopleura); 74–81 rows of paravertebral scales (versus 51–64 in M. melanopleura, 60–68 in M. mouroundavae, and 48–57 in M. nanus); 75–80 rows of ventral scales (versus 48–54 in M. minutus, 56–63 in M. melanopleura, 59–63 in M. nanus, 60 in M. macrolepis, 61 in M. ankodabensis, 63–67 in M. mouroundavae; relatively long toes, with 16–19 (most often 17 or 18) subdigital lamellae under the fourth (versus 5–6 in M. macrolepis, 6–9 in M. nanus, 10–11 in M. minutus, 13 in M. ankodabensis, 9–16 in M. melanopleura); 26 rows of scales around midbody (versus 18 in M. macrolepis, 20 in M. nanus, 20–22 in M. minutus, 22 in M. ankodabensis, 28–32 in M. mouroundavae, 30–32 in specimens of the "stumpffi" phenotype); presence of two well defined two-scales wide dark longitudinal stripes on the flank (versus six dark stripes in M. igneocaudatus, dorsum uniformly dark, without lateral stripes in M. minutus and M. nanus; pentadactyl forelimbs (versus 4–5 digits in M. nanus and 3–4 in M. sp. "baeus"); and more generally by the very characteristic snout shape and its slender body.
Additionally, M. arenicola is also distinguishable from the other species of the “polleni” species complex by its contrasted coloration, characterized by the presence of a pair of two-scale wide dark lateral lines extending from snout to hindlimbs, well defined all along the body (versus lateral lines well defined anteriorly, becoming one – or two parallel – very thin dashed line posteriorly to forelimbs in M. polleni and in the lined morph of M. stumpffi, and lateral lines reduced to very short dark streak extending from the snout to the ear-opening, progressively fading and disappearing on the neck in the uniform morph of M. stumpffi), and by the characteristic shape of its snout, being relatively long and acute in lateral aspect (shorter snout in M. polleni, and in lateral aspect more rounded both in M. polleni and M. stumpffi).
|Etymology||The specific epithet is a composite of the Latin arena (sand) and incola (inhabitant). It refers to the sand-dwelling habits of the species and is used as an invariable noun in apposition.|