The family Opilioacaridae (Parasitiformes: Opilioacarida) in Mexico, description of two new species and notes on biology and geographical distribution.

Two new species of Opilioacaridae from Mexico are described, Neocarus chactemalensis sp. nov. and N. comalensis sp. nov., and new records for N. texanus Chamberlin & Mulaik and N. veracruzensis Vazquez & Klompen are presented. Relative positions of internal structures of the ovipositor, a highly variable character, are described based on comparisons of invaginated and evaginated ovipositors. A study of records of Opilioacaridae in Mexico shows that the group is distributed across a wide range of ecosystems and elevations, from dry, semi-desert to wet tropical forest, and coastal plains to the altiplano (>2,000 m).