Geckolepis megalepis SCHERZ, DAZA, KÖHLER, VENCES & GLAW, 2017
Can you confirm these amateur observations of Geckolepis megalepis?
|Higher Taxa||Gekkonidae, Gekkota, Sauria, Squamata (lizards: geckos)|
|Synonym||Geckolepis megalepis SCHERZ, DAZA, KÖHLER, VENCES & GLAW 2017|
|Distribution||N Madagascar (Antsiranana)|
Type locality: east side of Ankarana National Park (12.9564°S, 49.1172°E, ca. 150 m elevation), Antsiranana Province, north Madagascar.
|Types||Holotype: ZSM 2126/2007 (FGZC 1144), an adult of unknown sex, collected on 3 March 2007 by P Bora, H Enting, F Glaw, A Knoll & J Köhler.|
Paratypes. ZSM 289/2004 (FGZC 554), probably a subadult, sex unknown, from between Mahamasina and the Petit Tsingy (exact coordinates not known, but ca. 12.9558°S, 49.1181°E, ca. 125 m a.s.l.), Ankarana National Park, Antsiranana Province, north Madagascar, collected 25 February 2004 by F Glaw, M Puente & R Randrianiaina; ZSM 232/2016 (FGZC 5476), an adult of unknown sex, from the private forest of the Ankarana Lodge (12.9613°S, 49.1499°E, 134 m a.s.l.), Ankarana massif, Antsiranana Province, north Madagascar, collected 28 August 2016 by F Glaw, K Glaw, T Glaw, Jaques & NA Raharinoro; FGZC 1606 (UADBA uncatalogued), sex and age unknown, from Petit Tsingy (ca. 12.9558°S, 49.1181°E, ca. 125 m a.s.l.), Ankarana National Park, Antsiranana Province, north Madagascar, collected 12 February 2008 by N D’Cruze, M Franzen, F Glaw & J Köhler.
|Diagnosis||Diagnosis. A species of the genus Geckolepis based on its overall morphology and large, fish-like scales (similar to cycloid scales in terms of the extent of overlap), as well as its phylogenetic position (Lemme et al., 2013; Fig. 1). Geckolepis megalepis differs from all of its congeners by the possession of the following suite of characters: innermost pair of postmental scales in broad contact (condition A/B, Fig. 4), SVL ≤ 69.5 mm, infralabials to anterior margin of eye 4.5–4.8, 17–18 scales rows around the midbody, 27–31 ventral scales between the postmentals and the vent, and the absence of a dark lateral stripe, and typical midbody dorsal scales measuring 7.3–8.3% of the SVL in length. Osteologically, G. megalepis is characterised by a narrow infraorbital fenestra, a bulging nasal cavity, nasals with straight sides, a well developed anterior extension of the subfrontal process, a notched premaxilla-vomer fenestra, scapular ray of scapulocoracoid not surpassing the clavicle, and posteriorly curved pubic tubercle of the pubis. Additionally, it is separated by an uncorrected pairwise genetic distance in the mitochondrial ND4 gene of ≥10.1% from all other lineages of Geckolepis and has a unique CMOS haplotype (Lemme et al., 2013).|
Geckolepis megalepis may be distinguished from G. maculata (note: because of the substantial uncertainty surrounding the identity of G. maculata, we here compare G. megalepis only to the holotype of that species, ZMB 9655, until such a time as its true affinities can be clarified; see Köhler et al. (2009) for a detailed morphological account of that specimen) by the combination of fewer scale rows around midbody (17–18 vs. 25), fewer ventral scales (27–31 vs. 32), larger relative scale size (typical midbody dorsal scale 7.3–8.3% of SVL vs. 5.4%), and the absence of a dark lateral head stripe (vs. presence); from G. typica by larger maximum size (SVL up to 69.5 mm vs. <57 mm), fewer scale rows around midbody (17–18 vs. 28–32), fewer ventral scales (27–31 vs. 42–49), postmental scale condition (A/B vs. D), and the absence of dark longitudinal stripes on the dorsum (vs. presence); from G. polylepis by larger maximum size (SVL up to 69.5 mm vs. <52 mm), fewer scale rows at midbody (17–18 vs. 30–37), fewer ventral scales (27–31 vs. 37–55), and the absence of dark longitudinal stripes on the dorsum (vs. presence); and from G. humbloti by fewer scale rows around midbody (17–18 vs. 22–30), more infralabials to the anterior margin of the eye (4.5–4.8 vs. 3–4), and fewer ventral scales (27–31 vs. 33–41).
For comparison of the osteology of the new species with Geckolepis maculata,
G. humbloti, and a specimen of OTU AB, see the Osteology of Geckolepis section below.
|Comment||Habitat: trees and tsingy limestone rock.|
Behavior: When captured, these geckos showed a strong tendency to autotomize large parts of their scales, leading to partly ‘naked’ geckos without any visible (bloody) lesions (Fig. 3C). In a subjective comparison this tendency appeared to be even more developed than in other Geckolepis species.
Sympatry: Lygodactylus expectatus, Phelsuma roesleri
Abundance: only known from its original description (Meiri et al. 2017).
|Etymology||The specific epithet is derived from the two Greek stems μεγας (mégas) meaning ‘very large’ and λεπ ́ις (lepís) meaning ‘scale’, and refers to the large size of the scales of this species in comparison to its congeners and other geckos, which aids also in its diagnosis.|