An order of extremely rare arachnids, also known as the Podogona, with a body less than 1 in. (25 mm) in length. Superficially, they resemble ticks in general appearance and movement, and are found only in tropical Africa and in the Americas, from the Amazon to Texas. The two anterior pairs of appendages are chelate. The terminal segments of the third legs of the male are modified as copulatory structures. Less than 25 modern species are known. The occurrence of several fossils from Carboniferous time suggests that the group was formerly more common. Virtually nothing is known about the reproduction, growth, and ecology of the Ricinulei.