Mesozoic stem-group paraneopteran insects from the Upper Triassic Cow Branch Formation of Virginia and North Carolina

Abstract Keimeliopteridae n. fam., a new family of stem-group paraneopteran insects containing two species, Keimelioptera solensis n. gen. n. sp. and K. rara n. gen. n. sp., is described from the Upper Triassic (Norian) Cow Branch Formation of the Solite deposit in Virginia and North Carolina, USA. A phylogenetic analysis using 16 terminal taxa and 68 morphological characters recovered Keimeliopteridae outside of crown Paraneoptera (bark lice, true lice, thrips, and hemipterans), as sister to Hypoperlidae + Paraneoptera sensu stricto. Keimeliopteridae can be definitively placed near Paraneoptera on the basis of the fusion of veins R + M + CuA into a common stem, the presence of an arched cua-cup crossvein, a simple CuP vein, and a two-branched CuA vein forming an areola postica. However, the plesiomorphic retention of pentamerous maxillary palpi, pentamerous tarsi, and probable cerci exclude Keimeliopteridae from crown Paraneoptera and necessitate the creation of this new family. Similar taxa are unknown from elsewhere during the late Paleozoic and early Mesozoic, which may be expected given the general rarity of shared taxa between Solite and coeval deposits. Keimeliopteridae is particularly significant due to the sparse Mesozoic record of Paraneoptera from the New World, and its discovery further demonstrates the significance of the Solite deposit as a window into the evolutionary history of insects following the End Permian Mass Extinction. UUID: http://zoobank.org/bb0e9f2f-dcb2-48ad-bd14-37f6f89fea0e