Kauglainetidae

Kauglainetidae is a small family of spiders in the infraorder Araneomorphae. It comprises two described genera and about a dozen described species, with a distribution focused in temperate forest regions of the southern hemisphere. Members are generally small to medium in size, with body lengths ranging roughly from 3 to 9 millimeters and a color pattern that varies from pale to brown. The eye pattern, leg proportions, and genital morphology are used to distinguish Kauglainetidae from related families. In males, the structure of the pedipalps is a key diagnostic feature, while females are identified by distinctive epigynal structures.

Taxonomy and systematics within Kauglainetidae have been subject to debate. The family was established to accommodate a clade sharing unique genitalia and silk-use traits, but its precise relationships to other small araneomorph families have remained unsettled. Molecular studies have yielded mixed results, with some analyses suggesting affinity to other small, ground-dwelling web builders and others indicating a more distant relationship within Araneomorphae. As a result, the internal composition and exact placement of Kauglainetidae continue to be revised as new data become available.

Genera described within the family include Kauglainetus and Nyctomorpha, with a total of about 12 species assigned to these groups. Species are typically found in leaf litter, under bark, or in crevices within montane or coastal temperate forests. They are predominantly nocturnal, feeding on small arthropods, and exhibit relatively simple silk architectures, such as small retreats or short silk lines.

Distribution and habitat extend across temperate regions of the southern hemisphere, including select areas of South America and nearby islands, where habitat complexity supports leaf-litter and bark-dwelling predators. Conservation status is generally not well defined for many species, reflecting limited survey data.