Curly-tailed lizard


The curly-tailed lizards belong to the family Leiocephalidae. One of the defining features of these lizards is that their tail often curls over. They were previously regarded as members of subfamily Leiocephalinae within the family Tropiduridae. There are presently 29 known species, all in the genus Leiocephalus.

Distribution

The curly-tailed lizards are native to the West Indies, with the extant species in the Bahamas, Turks and Caicos, Cayman Islands, Cuba, Hispaniola and nearby small islands. Additionally, Leiocephalus carinatus and Leiocephalus schreibersii have been introduced to Florida.

General anatomy

The curly-tailed lizards vary in size depending on species, but typically are approximately in snout-to-vent length. These lizards have no femoral pores, pterygoid teeth, or palatine teeth. Additionally, these lizards are observed to have overlapping scales.

Behavior

The curly-tailed lizards mostly forage on arthropods like insects, but also commonly take flowers and fruits. Large individuals will eat small vertebrates, including anoles.
As suggested by their name, most species of this family often lift their tail and curl it. This is done both when a potential predator is present and when not present, although in some curly-tailed lizard species it increases when one is present. It shows the fitness of the lizard to a would-be predator and—in the case of an attack—draws attention to the tail, which increases the lizard's chance of escaping. Although it has been suggested that it also functions as a territorial display, studies have been unable to find support for this, as the tail curling does not change when another member of the same species is present.

Conservation status

The conservation status of the species in this family varies greatly. Several species, for example Leiocephalus carinatus, are common and widespread. Others are rare and highly threatened, especially those restricted to a single small island or a single location on a larger island, like the critically endangered Leiocephalus altavelensis from Alto Velo Island and critically endangered Leiocephalus onaneyi from Guantánamo Province in Cuba. Primary threats to their survival are habitat loss and introduced predators. Several species are already extinct. Some of these are only known from fossil or subfossil remains and became extinct in the Pleistocene or pre-Columbian era, but others survived into recent history. Three species, Leiocephalus endomychus, Leiocephalus pratensis and Leiocephalus rhutidira, have not been seen since the 1960s and 1970s and are recognized as critically endangered, possibly extinct, by the IUCN. They are among the "most wanted" EDGE species.

Newly discovered species

Lizards of this family are diurnal and mostly inhabit fairly open habitats in a generally well-studied part of the world. Consequently, the majority of the species and subspecies already were scientifically described several decades ago. In 2016, the first new curly-tailed lizard since the early 1980s was described. The species was found in the coastal dunes of Bahía de las Calderas in the southwestern Dominican Republic. This species differs from the rest within Leiocephalidae in that its bony parietal table is U-shaped versus V-shaped, the males have 3-4 enlarged post-postcloacal scales versus 2, and there are specific sexual dimorphism trails.

Species and subspecies

The following species and subspecies, listed alphabetically by scientific name, are recognized as being valid by the Reptile Database.
Nota bene: A binomial authority or trinomial authority in parentheses indicates that the species or subspecies was originally described in a genus other than Leiocephalus.