Relictual-lineage
Guides
Ismaridae
Ismaridae is a small, relictual family of parasitoid wasps in the order Hymenoptera. The family contains two extant genera: Ismarus, with approximately 50–59 described species worldwide, and the fossil genus Lubomirus from Eocene amber. All species with known biology are hyperparasitoids that parasitize Dryinidae, which are themselves parasitoids of leafhoppers, planthoppers, and treehoppers. Formerly classified as a subfamily of Diapriidae, Ismaridae was elevated to family status based on distinct morphological differences, particularly the absence of a facial projection for antennal insertion and variable fusion of metasomal terga.
Leptoconops
black gnat, no-see-um
Leptoconops is a genus of biting midges (family Ceratopogonidae) commonly known as black gnats or no-see-ums. The genus has a relictual distribution with predominantly tropical and subtropical range, though some species extend to temperate regions including Russia and Canada. Adults are small blood-feeding insects; females are diurnal feeders on vertebrate blood. The genus represents one of the earliest existing lineages of biting midges, with fossil records dating to Cretaceous amber.
Platystoechotes
Platystoechotes is a genus of lacewings in the family Ithonidae, established by Carpenter in 1940. The genus belongs to the order Neuroptera, a group of insects characterized by their highly veined, membranous wings. Members of Ithonidae, including Platystoechotes, are often associated with warm, dry habitats and are among the more relictual lineages of Neuroptera.
Trogloraptoridae
Cave Robber Spiders
Trogloraptoridae is a family of spiders established in 2012 to accommodate the single genus Trogloraptor, found in caves and old-growth forests of the Pacific Northwest. The family was erected based on the unique morphology of Trogloraptor marchingtoni, which possesses distinctive raptorial claws unlike any other known spider. This discovery marked the first new family of spiders described from North America since the 1890s. The family represents a significant evolutionary lineage that has forced revisions to understanding of spider phylogeny.