Contributions to Zoology, 85 (1) – 2016V. Deepak; Varad B. Giri; Mohammad Asif; Sushil Kumar Dutta; Raju Vyas; Amod M. Zambre; Harshal Bhosale; K. Praveen Karanth: Systematics and phylogeny of Sitana (Reptilia: Agamidae) of Peninsular India, with the description of one new genus and five new species
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External morphology

Presence of enlarged scales on the body and thigh of Sitana is one of the key character in differentiating Sarada gen. nov. which lacks both these characters (Table 4, Fig. 6). There were no visible external morphological scale characters to differentiate species in the genus Sarada. Presence of enlarged spine like scales on the back of the head is a key character to differentiate Sitana spinaecephalus sp. nov. from the rest of the species in Sitana. Number of lamallae on the fourth toe, supralabials, infralabials, midbody scales, enlarged scales on the lateral side of body were all overlapping in Sitana (Table 5). Number of enlarged scale rows on the dewlap was relatively low in S. laticeps sp. nov. with marginal overlap with scale counts of S. visiri sp. nov. (Table 5). Ventral scale counts were also overlapping in S. ponticeriana, S. visiri sp. nov., Sitana spinaecephalus sp. nov. and S. laticeps sp. nov. (Table 5). However ventral counts were useful in differentiating the species from Sri Lanka and India. (See key to the species). Details on the characters which were used to distinguish each species and genus are given in the taxonomy and systematics section below.

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Fig. 6. The position and structure of the enlarged projecting scale on the thigh of Sitana. Note the complete absence of this scale in Sarada gen. nov. Clade 1: A. Sarada darwini sp. nov., B. Sarada deccanensis comb. nov., C. Sarada superba sp. nov.; Clade 2: D. Sitana spinaecephalus sp. nov., E. Sitana laticeps sp. nov.; Clade 3: F. Sitana ponticeriana, G. Sitana visiri sp. nov., H. Sitana cf. bahiri. Image not to scale.

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Table 4. Range of select scale counts Sarada gen. nov. specimens including the type series. Abbreviations, all measurements in mm, “_” = absent. Lam4 = Lamallae on fourth toe; SL = Supralabials; IL = infralabial; MBS = Mid body scales; ENL = enlarged scales on the flank region; ESD = enlarged scale rows in dewlap; VEN = number of ventral scales.

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Table 5. Range of select scale counts of Sitana specimens including the type series, sample size in brackets.. Abbreviations, all measurements in mm, “_” = absent. Lam4 = Lamellae on fourth toe; SL = Supralabials; IL = infralabial; MBS = Mid body scales; ENL = enlarged scales on the flank region; ESD = enlarged scale rows in dewlap; VEN = number of ventral scales.

Hemipenis morphology. Sarada superba sp. nov., S. ponticeriana, S. spinaecephalus sp. nov. have a bilobed hemipenis (Fig. 4). However, they differ in their microornementations; S. superba sp. nov. have large calyces at the base of the sulcal side of the hemipenis compared to S. spinaecephalus sp. nov. and S. ponticeria­na. Sitana spinaecephalus sp. nov. have a prominent grove on the asulcal side of the hemipenis which is absent in all other species (S2). Sarada darwini sp. nov., S. laticeps sp. nov. and S. visiri sp. nov. have a single lobed hemipenis (Fig. 4). They also differ considerably in their microornementation; Sarada darwini sp. nov. have relatively less calyces on the asulcal side (only on the apex) compared to S. laticeps and S. visiri in which the calyces extend further down (S2). S. visiri have several smaller calyces on the center of the apical region on the asucal side whereas in S. laticeps and S. darwini they are more or less uniform (S2). More detailed descriptions of the hemipenies of each species is given in the species description section (appendix).

Osteology. In Sarada darwini sp. nov., S. decca­nensis, Sitana ponticeriana and S. spinaecephalus the skull is subpentagonal in outline. Width of supratemporal fossa less than or equal to 60% of length. Splenial fused with the surrounding mandibular. The hyoid appears to be mostly bony, except the tip of the entoglossal process, tip of ceratobranchial I, tip of epibranchial I and the ceratohyals which are cartilaginous. The ceratobranchial is evidently longer in male than the female owing to the large dewlap in males. Several skeletal characters overlap between the four species (Table 6) except a few; Sitana ponticeriana and S. spinaecephalus n.sp. have 19 vertebrae excluding atlas and axis whereas S. darwini and S. decca­nensis only have 18. Sitana ponticeriana and S. spinaecephalus n.sp. have four phalanges on the fourth toe whereas S. darwini and S. deccanensis have five.

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Table 6. Select osteological characters & measurements of representative species from the genus Sitana & Sarada gen. nov.