Cosmetidae, with around 700 species, is the second most diverse family of the Suborder Laniatores. They are distributed from Argentina to southern USA, most diverse in northern South America, Central America and Mexico. This Nearctic-Neotropical family comprises Opiliones with elaborate white/yellow/green/orange/red stripes and spots on the dorsal scutum and peculiar pedipalps strongly compressed and applied on the chelicerae.
The Cosmetidae are endemic of the New World. The peak of their diversity is in northern South America, Central America, and Mexico, where maybe one third to half of species of Opiliones are represented by this single family; they are numerous in Amazonian and Andean realms and also in the Caribbean. They are absent in Chile. They also reach southwards as far as Argentina and even southern Brazil (genus Metalibitia). There are a few species in the Brazilian Atlantic Forest, mostly belonging to the genus Metavononoides. A few species now in Vonones reach far northwards into the USA, where they occur in many of the southern states. source