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We describe two new species of the lacertid genus Ophisops based on a series of 19 specimens from semi-arid habitats in the states of Gujarat and Rajasthan in northwestern India, provide a description of Ophisops microlepis sensu stricto, and a key to Indian Ophisops. Ophisops pushkarensis sp. nov. and Ophisops kutchensis sp. nov. are allied to Ophisops microlepis and can be diagnosed from all other Indian Ophisops by the fusion of the lower and upper eyelids, their large body size (snout to vent length > 50 mm), and ≥ 50 scales around midbody. They differ from O. microlepis and each other in the number of scales around midbody, the number of dorsal scales, subtle colour pattern differences, as well as uncorrected mitochondrial sequence divergence (6–9%). These are some of the only known endemic reptiles in these semi-arid landscapes and indicate that many other such habitats may harbour endemic biodiversity.

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Aim India is dominated by tropical grassy biomes (TGBs), traditionally considered seres or degraded forest, with low diversity relative to the restricted, ancestral wet zone. It is unclear if Indian grasslands and other open habitats are anthropogenically derived or native, old-growth habitats; without a clear timescale of grassland evolution. One way to understand grassland evolution is to study the diversification in taxa restricted to open habitats. We use a dated phylogeny of Ophisops to address questions related to the origin, diversification and inter-relationships of Indian and Saharo-Arabian Ophisops, and ultimately the origin of Indian grasslands and open habitats. Location The Indian subcontinent; the Saharo-Arabian Realm. Methods We generated up to 2736 base pairs of aligned sequence data (one mitochondrial, two nuclear genes) for Indian lacertids and reconstructed phylogenetic relationships using maximum likelihood and Bayesian inference. We use a fossil-calibrated timetree, diversification analyses and ancestral area reconstructions to test the hypotheses of origin and relationships with Saharo-Arabian Ophisops. Results Ophisops is strongly supported as monophyletic, with a basal split into a large-bodied (LBC) and small-bodied clade (SBC). The Saharo-Arabian species are nested within the Indian species in the LBC. Species diversity in Indian Ophisops is grossly underestimated, with 26–47 candidate species. Ophisops began diversifying in the late Oligocene with significant rate shifts in the late Miocene-Pliocene and Pleistocene within the SBC. Main conclusions Our results are consistent with an ancient origin of grassland taxa and TGBs in India. Ophisops is a dramatic example of overlooked cryptic diversity outside forests, with ~30 species where five were known. Ophisops dispersed into India from the Saharo-Arabian Realm in the Oligocene with a back dispersal in the Middle Miocene, a novel biogeographical pattern. Diversification in the SBC of Ophisops increased 8-fold during the global C4 grassland expansion. Indian TGBs are old-growth ecosystems that need urgent conservation attention.

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The basic anatomy of the lacertid hemipenis (intromittent organ) and methods for its investigation are described. In many members of the Lacertidae, the hemipenis has a structure quite unlike that of other squamate reptiles: the distal lobes of the retracted organ are complexly folded and there is a well-defined supporting structure of dense connective tissue, the armature. This incorporates blood sinuses and has an intramuscular portion embedded in the m. retractor penis magnus and two club-shaped bodies, the clavulae, that support the lobes in the erect organ. Unarmatured hemipenes occur in some lacertids and, like those of other squamates, possess sac-like lobes in the retracted state, but they are singular in having the lobes invested by the m. retractor penis magnus. It is argued that many of these apparently primitive hemipenes are in fact secondary derivatives of the armatured type. There is considerable inter-specific variation in hemipenial structure which is described systematically. In some cases this involves differences in size, asymmetry and simplification, which may arise as physical isolating mechanisms and is useful in distinguishing otherwise very similar species, particularly in the genus Mesalina (p. 1253). Other shared derived hemipenial features provide useful information about relationships between species and higher taxa and a summary of the hypotheses that they support is given (p. 1254).

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This paper deals with the reptile fauna of Gujarat State, and is primarily based on a collection made by the author during the Gujarat survey between 1989-1993. Information from earlier collections from Gujarat in the Zoological Survey of India, have also been included, as are data from the literature. To increase the usefulness of the paper, species that have ranges approaching the State have also been included. Altogether, 66 species in 50 genera and 18 families that are known from Gujarat have been dealt with in this report. Keys, diagnostic characters, measurements and distributional notes have been incorporated in the paper. Two squamate species, Hemidactylus triedrus and Lygosoma lineata are being reported for the first time from Gujarat.

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Aim Body size is instrumental in influencing animal physiology, morphology, ecology and evolution, as well as extinction risk. I examine several hypotheses regarding the influence of body size on lizard evolution and extinction risk, assessing whether body size influences, or is influenced by, species richness, herbivory, island dwelling and extinction risk. Location World-wide. Methods I used literature data and measurements of museum and live specimens to estimate lizard body size distributions. Results I obtained body size data for 99% of the world`s lizard species. The body size–frequency distribution is highly modal and right skewed and similar distributions characterize most lizard families and lizard assemblages across biogeographical realms. There is a strong negative correlation between mean body size within families and species richness. Herbivorous lizards are larger than omnivorous and carnivorous ones, and aquatic lizards are larger than non-aquatic species. Diurnal activity is associated with small body size. Insular lizards tend towards both extremes of the size spectrum. Extinction risk increases with body size of species for which risk has been assessed. Main conclusions Small size seems to promote fast diversification of disparate body plans. The absence of mammalian predators allows insular lizards to attain larger body sizes by means of release from predation and allows them to evolve into the top predator niche. Island living also promotes a high frequency of herbivory, which is also associated with large size. Aquatic and nocturnal lizards probably evolve large size because of thermal constraints. The association between large size and high extinction risk, however, probably reflects a bias in the species in which risk has been studied.

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Over the past two decades many checklists of reptiles of India and adjacent countries have been published. These publications have furthered the growth of knowledge on systematics, distribution and biogeography of Indian reptiles, and the field of herpetology in India in general. However, the reporting format of most such checklists of Indian reptiles does not provide a basis for direct verification of the information presented. As a result, mistakes in the inclusion and omission of species have been perpetuated and the exact number of reptile species reported from India still remains unclear. A verification of the current listings based on distributional records and review of published checklists revealed that 199 species of lizards (Reptilia: Sauria) are currently validly reported on the basis of distributional records within the boundaries of India. Seventeen other lizard species have erroneously been included in earlier checklists of Indian reptiles. Omissions of species by these checklists have been even more numerous than erroneous inclusions. In this paper, I present a plea to report species lists as annotated checklists which corroborate the inclusion and omission of species by providing valid source references or notes.