Acipenseriformes is an order of basal ray-finned fishes that includes living and fossil sturgeons and paddlefishes (Acipenseroidei), as well as the extinct families Chondrosteidae and Peipiaosteidae. They are the second earliest diverging group of living ray-finned fish after the bichirs. Despite being early diverging, they are highly derived, having only weakly ossified skeletons that are mostly made of cartilage, and in modern representatives highly modified skulls.
The Cupedidae are a small family of beetles, notable for the square pattern of "windows" on their elytra, which give the family their common name of reticulated beetles.
Bittacidae is a family of scorpionflies commonly called hangingflies or hanging scorpionflies.
The Ptychopteridae, phantom crane flies, are a small family of nematocerous Diptera. Superficially similar in appearance to other "tipuloid" families, they lack the ocelli of the Trichoceridae, the five-branched radial vein of the Tanyderidae, and the two anal veins that reach the wing margins of the Tipulidae. They are usually allied with the Tanyderidae based on similarities of the mesonotal suture, this group being called the Ptychopteromorpha.
Pelecinidae is a family of parasitic wasps in the superfamily Proctotrupoidea. It contains only one living genus, Pelecinus, with three species known from the Americas. The earliest fossil species are known from the Jurassic, and the group was highly diverse during the Cretaceous. Members of Pelecinus are parasitic on larval beetles, flies, green lacewings, and sawflies.
Nemonychidae is a small family of weevils, placed within the primitive weevil group because they have straight rather than geniculate (elbowed) antennae. They are often called pine flower weevils. As in the Anthribidae, the labrum appears as a separate segment to the clypeus, and the maxillary palps are long and projecting. Nemonychidae have all ventrites free, while Anthribidae have ventrites 1-4 connate or partially fused. Nemonychidae lack lateral carinae on the pronotum, while these are usually present, though may be short, in Anthribidae.
Protodiplatyidae is an extinct family of earwigs. It is one of three families in the suborder Archidermaptera, alongside Dermapteridae and Turanovia. Species are known from Jurassic and Early Cretaceous fossils and have unsegmented cerci and tarsi with four to five segments.
Peipiaosteus is an extinct genus of prehistoric chondrostean ray-finned fish. Its fossils are found in the Early Cretaceous Jiufotang Formation, Pani Lake, Liaoning Province, China.
Coptoclavidae is an extinct family of aquatic beetles in the suborder Adephaga. The Coptoclavidae lived from the Late Triassic to the Early Cretaceous. Coptoclavidae is a member of the adephagan clade Dytiscoidea, which contains other aquatic beetles. Suggested reasons for their extinction to include the rise of teleost fish, or competition with Gyrinidae and Dytiscidae, which possess defensive secretions and sucking channels in the mandibles of larvae, which coptoclavids likely lacked. It has been suggested that the genus Timarchopsis and the subfamily Timarchopsinae are only distantly related to other coptoclavids based on cladistic analysis, with Timarchopsis being more closely related to geadephagans like carabids and trachypachids instead. Another study also suggested similarly for Coptoclavisca and possibly other coptoclaviscines.
Protorabinae is an extinct subfamily of beetles in the family Carabidae. It contains 36 species in 13 genera, all extinct.
Mesoraphidiidae is an extinct family of snakeflies in the suborder Raphidiomorpha. The family lived from the Late Jurassic through the Late Cretaceous and is known from twenty-five genera. Mesoraphidiids have been found as both compression fossils and as inclusions in amber. The family was first proposed in 1925 by the Russian paleoentomologist Andrey Vasilyevich Martynov based on Upper Jurassic fossils recovered in Kazakhstan. The family was expanded in 2002 by the synonymizing of several other proposed snakefly families. The family was divided into three subfamilies and one tribe in a 2011 paper, further clarifying the relationships of the included genera.
Heloridae is a family of wasps in the order Hymenoptera known primarily from fossils, and only one extant genus, Helorus, with 12 species found worldwide. Members of Helorus are parasitic on green lacewings.
Roproniidae is a family of wasps in the order Hymenoptera, of which only two genera are still extant, the others being fossils.
Blattulidae is an extinct family of cockroaches known from the Triassic to the Late Cretaceous. Their distinguishing characteristics include "forewing has long Sc, regular venation with distinct intercalaries and hindwing has simple CuP, branched A1."
Eremochaetidae is an extinct family of brachyceran flies known from the Jurassic and Cretaceous periods of Asia. It is part of the extinct superfamily Archisargoidea. The morphology of the ovipositor of the only 3 dimensionally preserved genus Zhenia was initially interpreted as evidence of being an endoparasitoid of arthropods, however a subsequent study suggested that the ovipositor was used to deposit its eggs in plant material, similar to members of Tephritoidea. In a phylogenetic analysis, Ermochaetidae was found to be monophyletic, surrounded by a paraphyletic Archisargidae.
Archisargidae is an extinct family of brachyceran flies known from the Jurassic and Cretaceous periods. It is part of the extinct superfamily Archisargoidea. Most members of the family are known from the Callovian-Oxfordian Daohugou biota of Inner Mongolia, China, and the equivalently aged Karabastau Formation of Kazakhstan. The family has been found to be paraphyletic with respect to Eremochaetidae in a cladistic analysis.
Praeaulacidae is an extinct family of Mesozoic parasitic wasps in the suborder Evanioidea. It among the earliest known families of the group and is characterised by more complete wing venation in comparison to other members of the suborder. It has been found that Othniodellithidae is nested within Praeaulacidae via cladistic analysis.
Mesochrysopidae is an extinct family of lacewings known from the Jurassic and Cretaceous periods. They are considered to be closely related to green lacewings of the family Chrysopidae. The family are also alternatively considered a paraphyletic grade leading up to crown Chrysopidae.
Susumanioidea is an extinct superfamily of Phasmatodea, known from the Middle Jurassic to Eocene. They lie outside the modern crown group of Phasmatodea. Members of the group typically possess large, fully developed wings.
Orthophlebiidae is an extinct family of scorpionflies known from the Triassic to Cretaceous, belonging to the superfamily Panorpoidea. The family is poorly defined and is probably paraphyletic, representing many primitive members of Panorpoidea with most species only known from isolated wings, and has such been considered a wastebasket taxon.
