Cretaceous-survivors
Guides
Oonopidae
Goblin spiders
Oonopidae, commonly known as goblin spiders, is a diverse family of minute spiders comprising approximately 2,000 described species across 115 genera worldwide, with total species diversity estimated at 2,000–2,500. These spiders are characterized by their tiny size (typically 1–3 mm), reduced eye number (usually six, though some species have four, two, or are completely eyeless), and frequently exhibit unusual morphological modifications in males. The family shows remarkable morphological diversity including hardened abdominal plates (scuta), modified mouthparts, sternal pouches, and elaborate pedipalp structures. Goblin spiders are predominantly ground-dwelling, inhabiting leaf litter, soil, and rock crevices, with some lineages adapted to canopy habitats, caves, or termite nests. The family has an extensive fossil record in amber deposits dating back over 100 million years, with Orchestina already widespread by the end of the Cretaceous.
Sisyridae
spongillaflies, spongeflies
Sisyridae, commonly known as spongillaflies or spongeflies, are a small family of aquatic Neuroptera with approximately 60 extant species worldwide. Adults are small, brownish or greyish insects resembling brown lacewings (Hemerobiidae), with forewings spanning 4–10 mm. The family is distinguished by their unique larval biology: larvae are aquatic and obligate predators of freshwater sponges (Porifera: Spongillidae) and bryozoans (Phylactolaemata), using elongated piercing-sucking mouthparts to extract cell contents. Larvae possess seven pairs of jointed, movable tracheal gills on the abdomen—a trait unique among extant insects. The family has a fossil record extending to the Late Cretaceous, with two extant subfamilies (Sisyrinae and Paradoxosisyrinae) and four living genera: Climacia, Sisyborina, Sisyra, and Sisyrina.