Fossil-insects
Guides
Anisopodidae
Wood Gnats, Window-Gnats
Anisopodidae is a small, cosmopolitan family of gnat-like flies comprising 154 described extant species across 15 genera, with additional fossil taxa known from the Jurassic through Cenozoic. Commonly called wood gnats or window-gnats, most species are small to medium-sized (4–12 mm), though genera Olbiogaster and Lobogaster are notably larger (17–18 mm) with distinctive spatulated abdomens. The family's phylogenetic placement remains controversial, with proposals ranging from sister group to Brachycera to recognition as multiple distinct families. Some authors recognize four separate families: Anisopodidae, Mycetobiidae, Olbiogastridae, and Valeseguyidae.
Baetiscidae
armored mayflies
Baetiscidae is a family of mayflies distinguished by their heavily armored nymphs bearing a robust, spiked thoracic notal shield that extends over part of the abdomen. The family contains a single extant genus, Baetisca, with approximately 12 species endemic to North America. Three extinct genera (Protobaetisca, Balticobaetisca, Koonwarrabaetisca) are known from Cretaceous and Eocene deposits, indicating a Pangean origin for the family by at least the Early Jurassic. Together with Prosopistomatidae, Baetiscidae forms the clade Carapacea, characterized by specialized larval armor.
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.
Tanyderidae
Primitive crane flies
Tanyderidae, commonly called primitive crane flies, are a small family of long, delicate nematoceran flies with about 40 extant species. They represent a relict lineage within Diptera, retaining primitive wing venation including five complete branches of the radial vein. Adults are recognized by their spotted or mottled wings and are typically found near streams, often resting on vegetation or hanging beneath bridges. Larvae inhabit wet, decaying wood or sandy and gravelly stream margins. The family has an extensive fossil record dating to the Late Triassic, with numerous extinct genera known from amber deposits.