Palpal-chaetotaxy
Guides
Opilioacaridae
Opilioacarid mites, Primitive mites
Opilioacaridae is the sole family in the order Opilioacarida, comprising approximately 13 genera of rare, relatively large mites (1.5–2.5 mm). These mites are considered primitive due to retention of six pairs of eyes and abdominal segmentation, traits lost in other mite lineages. Historically treated as distinct from both Acariformes and Parasitiformes, molecular phylogenetics now places them within Parasitiformes. The family exhibits a disjunct global distribution with populations in semi-arid and tropical regions, including caves, leaf-litter, and rock habitats.