The cranial osteology and dentition in the scincid lizards of the genusChalcides(Reptilia, Scincidae)

Abstract

The skull and dentition were analysed and compared in a number of species of Old World scincid lizards, genus Chalcides (including Sphenops). The major differences are related to the decrease in absolute skull size, which entails an increase in the relative size of the otic capsule and the progressive obliteration of the supra-and post-temporal fossae. The greatest reduction of the post-temporal fossa is observed in the smallest species, resulting in close proximity of parietal and supraoccipital bones and in a possible reduction of metakinesis. Another major difference concerns the relationships between pre-and post-frontal bones, widely separated in Chalcides sensu stricto and articulated in the taxa formerly attributed to the genus Sphenops. This close connection likely represents an internal reinforcement preventing deflection or fracture in these sand-swimming taxa by reducing the mobility of the fronto-parietal mesokinetic joint. The teeth are conical, pleurodont and ankylosed to the inner margin of the dentary, pre-maxilla and maxilla. They exhibit two cusps separated by a single groove that probably aid in grasping hard-bodied prey. The pre-maxillae usually bear an odd number of teeth; the number of pre-maxillary, maxillary and dentary teeth does not seem to increase with skull size. In all cases, the number of dentary teeth exceeds that of maxillary ones.

Slow evolving satellite DNAs: the case of a centromeric satellite in Chalcides ocellatus (Forskål, 1775) (Reptilia, Scincidae)

“…The genus Chalcides belongs to the femily Scincidae and currently comprises 30 accepted species distributed in the Macaronesian and Mediterranean areas and from central and eastem Africa to Pakistan, with the maximum of species diversity in Morocco and surrounding areas (see Caputo, 2004;Carranza et al, 2008). The ocellated skink (Chalcides ocellatus) has the wider geographic distribution within this genus, being distributed in Africa (North of Sahara, from Morocco to Egypt), Italy (Sicily and Sardinia), some mainland areas of Greece, some islands of eastem Mediterranean, South Anatolia, the Near East, Iraq, Arabian Peninsula and most of Somalia, and coastal areas of Iran and Pakistan where its indigenous presence is doubtful (see Sindaco and Jeremcenko, 2008).…”

Phylogeographic inferences from the mtDNA variation of the three‐toed skink, Chalcides chalcides (Reptilia: Scincidae)

“…Additionally, four specimens of C. striatus and four of C. boulengeri (subgenus Sphenops, sensu Caputo, 2004) were included as outgroups in the phylogenetic analysis. Two segments of mtDNA were PCR-amplified: a segment of approximately 2.7 kb comprising NADH dehydrogenase subunits 1 and 2 (ND-1/2) was amplified using the primers L3827 and H6313 (Sorenson et al,'99); a segment of about 2.4 kb comprising NADH dehydrogenase subunits 3, 4L and 4 (ND-3/4) was amplified with the primers ND-3/4 F and ND-3/4 R designed by Nielsen et al ('98).…”

Mitochondrial DNA reveals high genetic divergence between populations of Chalcides mertensi Klausewitz, 1954 (Reptilia: Scincidae) from Tunisia

“…In fact, 16 out of the 30 currently recognized species in this genus and all its main lineages occur in this area (Caputo, 2004;Carranza et al, 2008). This high degree of diversification is probably related to the complex palaeogeographic and palaeoclimatic history of this region.…”