Calotes Cuvier, 1817

The genus Calotes Cuvier, 1817 with the type species Lacerta calotes Linnaeus, 1758 belongs to the subfamily Draconinae of the family Agamidae, containing 26 species. The geographical distribution of this genus is largely restricted to South Asia and Indo-china, except for one isolated species Calotes nigriplicatus Hallermann, 2000 found in Ambon Island in Indonesia. The greatest diversity of the genus is in the Western Ghats and Sri Lanka. Four species of Calotes ( C. grandisquamis, C. nemoricola, Calotes cf. versicolor, Calotes calotes) are known from the Western Ghats of which two are endemic to this region.

Diagnosis. Medium to large sized agamids with a relatively broader head; dorsal and lateral scales uniform, arranged in rows of backwardly pointed scales; dorsal and nuchal crest more or less developed; groups or rows of spines from eye to above tympanum; often an antehumeral skin fold or pit present covered with small scales; gular sac usually present; tympanum naked; tail long and slender, usually swollen and rounded at the base in males; no preanal or femoral pores.

Distribution. Lizards belonging to the Genus Calotes are widely distributed across Iran, Afghanistan, Bhutan, Bangladesh, Maldives, Nepal, India, Pakistan and Sri Lanka as well as southern China; parts of Myanmar, Thailand, Laos, Cambodia, Vietnam, Peninsular Malaysia and parts of Indonesia. Moreover, Calotes versicolor has been introduced into Kenya, Borneo, Sulawesi, Seychelles, Mauritius, Oman and Florida (USA) (Das et al. 2008; Manthey, 2008; Uetz and Hošek, 2016).

Taxonomic groups. Smith (1935) separated members of the genus Calotes into four distinct groups, I. C. cristatella group, II. C. microlepis group, III. C. versicolor group, and IV. C. liocephalus group, each composed of multiple species and another group composed of two dwarf species based on their morphological similarities. Later, Moody (1980) separated the genus into four different genera, namely Bronchocela Kaup, 1827 (group I of Smith), Dendragama Doria, 1888, Pseudocalotes Fitzinger, 1843 (group II of Smith) and Calotes (group III, IV and the two dwarf species of Smith). Most of the Calotes species occurring in the Western Ghats belong to the Calotes versicolor group of Smith (1935) except Calotes rouxii and Calotes ellioti, which belong to the dwarf group. Here, we transfer these two species to the new genus Monilesaurus gen. nov. In the present study, we follow Smith’s species groups for taxonomic accounts and morphological comparisons. Since Smith, there have been various new additions to the genus Calotes and to the Calotes versicolor group. In this study, we compare each individual species only with members of their own group.

Calotes versicolor group. Members of the C. versicolor group are characterized by a medium to large adult body size; body more or less compressed, dorsal and lateral scales large, uniform, smooth or feebly keeled and oriented postero-dorsally; antehumeral fold absent; dorsal scales larger than the ventrals except in C. calotes where it is equal to or slightly smaller than the ventrals; nuchal and dorsal crest well developed, continuous, at least till behind the shoulders; postorbital spine absent except in C. emma Gray, 1845; supratympanic spines in form of paired patches or as a single longitudinal series of spines (Fig. 4 & 5). For taxonomic comparisons, we add the recently designated C. minor to Smith’s C. versicolor group (See Deepak et al. 2015).

Content. Calotes bachae Hartmann, Geissler, Poyarkov, Ihlow, Galoyan, Rödder & Böhme, 2013; C. bhutanensis Biswas, 1975; C. calotes; C. ceylonensis Müller, 1887; C. chincollium Vindum, 2003; C. desilvai Bahir & Maduwage, 2005; C. emma; C. grandisquamis, C. hutunwini Zug & Vindum, 2006; C. irawadi Zug, Grown, Schulte & Vindum, 2006; C. jerdoni Günther, 1870; C. liocephalus Günther, 1872; C. liolepis Boulenger, 1885; C. versicolor, C. manamendrai Amarasinghe & Karunarathna, 2014; C. maria Gray, 1845; C. medgoensis Zhao & Li, 1984; C. minor, C. mystaceus Duméril & Bibron, 1837; C. nemoricola, C. nigrilabris Peters, 1860; C. nigriplicatus Hallermann, 2000 and C. pethiyagodai Amarasinghe, Karunarathna, Hallermann, Fujinuma, Grillitsch & Campbell, 2014 .

Diagnosis. All the species belonging to this group can be differentiated from the other groups of Calotes based on the combination of the following characters: From members of the genus Monilesaurus gen.nov., they can be easily distinguished morphologically based on a larger adult size (vs. smaller); dorsal and lateral scales rows directed posterodorsally, much larger in size (vs. posteroventrally, smaller in size); dorsal and lateral scales larger than ventrals, except in C. calotes (vs. not larger than ventrals) (Fig. 4–5 vs 6–7) and absence of antehumeral fold (vs. presence of a well developed antehumeral fold) (Fig. 10). From members of the genus Psammophilus, group they can be distinguished by the presence of compressed body shape (vs. depressed) (Fig. 4–5 vs 8a); absence of an antehumeral fold (vs. antehumeral fold present) (Fig. 10f vs 10g); lateral scales much larger (vs. smaller); presence of well developed nuchal crest (vs. reduced) and lesser number of midbody scale rows, less than 60 (vs. scale rows higher in number, more than 80). From Microauris gen. nov. by having a relatively large tympanum (Fig. 9a vs 9b); scales on head large uniform shield like (vs. small, sub-triangular) (Fig. 10b vs 10d).