Leiocephalidae, also known as the curlytail lizards or curly-tailed lizards, is a family of iguanian lizards restricted to the West Indies. One of the defining features of these lizards is that their tail often curls over. They were previously regarded as members of the subfamily Leiocephalinae within the family Tropiduridae. There are presently 29 known species, all in the genus Leiocephalus. Taxonomy Phylogenetic evidence supports Leiocephalidae being the most basal extant member of the clade Pleurodonta, with it diverging from the rest of the suborder as early as the Late Cretaceous, about 91 million years ago. As with many other higher-order taxa endemic to the Caribbean, it likely colonized the Antilles from South America during the Cenozoic; however, its deep divergence time from other lizards supports a much more complex and less straightforward history in the West Indies compared to other modern taxa. Phylogenetic analysis on the genus supports some members of the now-extinct Lesser Antillean Leiocephalus radiation being the most basal of the recent Leiocephalus, with the last-surviving members of this group, L. herminieri and L. roquetus , sharing traits not present in other curlytail lizards from the Greater Antilles and other areas, such as the absence of enlarged snout scales. The second most basal of the recent curlytail lizards is another recently extinct species, L. eremitus from Navassa, followed by all other members of the genus from the Bahamas and Greater Antilles. Another extinct species from the Lesser Antilles known only from fossil remains, L. cuneus of Antigua and Barbuda, is thought to be more closely related to more derived Leiocephalus from the Bahamas and Greater Antilles, such as L. carinatus, L. greenwayi and L. punctatus, than to the other, more basal Lesser Antillean and Navassa species. Distribution Curlytail lizards are native to the West Indies, with the extant (living) species in the Bahamas, Turks and Caicos, Cayman Islands, Cuba, Hispaniola (Haiti and the Dominican Republic) and nearby small islands. Additionally, Leiocephalus carinatus and Leiocephalus schreibersii have been introduced to Florida. Former distribution Curlytail lizards formerly had a much wider native range, being distributed south to Jamaica and east to Puerto Rico and several of the Lesser Antilles. They went extinct in most of this range during the Quaternary extinction (with some such as the Jamaican taxon L. jamaicensis going extinct during the Late Pleistocene, well before the arrival of the first Amerindians to the area), but some