Relictual-distribution
Guides
Dasycerinae
Dasycerinae is a small subfamily of rove beetles (Staphylinidae) containing one extant genus (Dasycerus) and three extinct genera. These beetles are characterized by their compact body form with elytra that cover or nearly cover the abdomen, unlike the typically abbreviated elytra of most rove beetles. The subfamily is notable for its relictual distribution and association with moist forest habitats.
Pimoidae
Large Hammock-web Spiders
Pimoidae is a small family of araneomorph spiders established by Wunderlich in 1986, closely related to Linyphiidae and sometimes treated as synonymous with that family. As re-circumscribed in 2021, it is monophyletic and contains approximately 90 species in two genera, primarily Pimoa and Weintrauboa. Members are commonly known as large hammock-web spiders due to their substantial size relative to linyphiids and their horizontal, net-like webs. The family has a fragmented relictual distribution across the Pacific coast of North America, the Cantabrian Mountains of Spain, the European Alps, and the Himalayas and adjacent regions of Asia.
Pleocoma
rain beetles
Pleocoma is the sole extant genus of Pleocomidae, a family endemic to the Pacific states of North America. These beetles are notable for their extreme subterranean lifestyle, with adults emerging only during fall and winter rains to mate. The genus name derives from Greek words for 'abundant hair,' referring to the dense ventral hair covering. Adults are non-feeding, while larvae are root-feeders with exceptionally long development periods of up to 13 years.
Scarabaeoidearain-beetlessubterraneannon-feeding-adultslong-lived-larvaepheromone-mediated-matingendemicNearcticrelictual-distributionCretaceous-originpest-of-Christmas-treeslamellate-antennaeflightless-femalesrain-triggered-emergenceCalifornia-faunaOregon-faunaWashington-faunaroot-feeding-larvaeextreme-seasonalitylight-attracted-malesThanerocleridae
Thanerocleridae is a small family of predaceous cleroid beetles comprising 36 extant species in 10 genera. Formerly classified as a subfamily of Cleridae, it was elevated to family rank based on molecular data. The family has a cosmopolitan distribution concentrated in tropical and subtropical regions, with one relictual temperate genus (Zenodosus) in North America. Species occupy habitats associated with wood-decaying fungi and tree bark, where they prey on small beetles.
Vermileonidae
wormlions
Vermileonidae is a small family of Brachycera flies comprising fewer than 80 described species in 11 genera. The family is notable for its unusual biology: larvae construct conical pitfall traps in sand to capture prey, while adults are slender, long-legged flies that visit flowers for nectar. Historically classified within Rhagionidae, Vermileonidae is now recognized as a distinct family due to marked morphological and biological differences. The group has a relictual distribution concentrated in arid regions of Africa and the western Mediterranean, with additional species in Asia and the Nearctic.