New classification of Fan-throated lizards from India
We provide taxonomic accounts for all the presently known Sitana species from India, including the formal description of five new species. Species are classified into four groups: 1- the S. ponticeriana clade, found in coastal and Inland Tamil Nadu and coastal Sri Lanka; 2- the S. spinaecephalus clade, found from the Mysore Plateau to Ajmer in Rajasthan; 3- the Sarada deccanensis clade, found on the Deccan Plains and Plateau; 4- the Sitana sivalensis complex, comprising Sitana sivalensis, Sitana schleichi, and Sitana fusca, found in the Terai region of Nepal. External morphological diagnosis is only possible for males of different populations, therefore most of the diagnoses are based on males. However, we have provided details of morphometric measurements and scale counts for both sexes. All morphometric measurements in the text are reported as (mean ± SD). We only compare the mitochondrial sequences (ND2 gene) to show genetic divergence. The dewlap to trunk ratio is variable for different species and is one of the key characters for identifying Sitana spp. (Amarasinghe et al., 2015). For ease of identification, dewlap sizes were classified into four groups which are used in the key to the genus and species of Sitana and Sarada gen. nov. 1. Small: dewlap extending only to the forearm insertion, 2. Medium: dewlap extends beyond the forearm insertion up to 30% of trunk length, 3. Large: dewlap extends 31 to 50% of the trunk length. 4. Very large: dewlap extends more than 50% of the length of the trunk.