A revision of the late Eocene snakeflies (Raphidioptera) of the Florissant Formation, Colorado, with special reference to the wing venation of the Raphidiomorpha.

Abstract

The snakeflies (Raphidioptera) of the late Eocene Florissant Formation (Colorado, USA) are revised. Seven species of Raphidiidae are assigned to three genera, i.e., Megaraphidia Cockerell, 1907, Archiraphidia Handlirsch, 1910, and Florissantoraphidia gen. nov. Dictyoraphidia Handlirsch, 1910 is assigned to Baissopteridae, a first Cenozoic record of the family. Archiraphidia tumulata (Scudder, 1890), A. tranquilla (Scudder, 1890) and A.? somnolenta (Scudder, 1890), stat. res. are treated as distinct species, and A. eventa (Scudder, 1890) as a new synonym of A. tranquilla. The lectotype of A. eventa is designated. 'Raphidia' exhumata Cockerell, 1909 is transferred to Megaraphidia. 'Raphidia' mortua Rohwer, 1909 and 'R.' funerata Engel, 2003 constitute Florissantoraphidia gen. nov. Our findings support the treatment of the single Florissant species of Inocelliidae as preliminary assigned to Fibla Navás, 1915. We examine venational synapomorphies of Raphidiomorpha and provide a new diagnosis for it based on these characters. We evaluate putative derived venational character states of 'Neoraphidioptera' (Inocelliidae and Raphidiidae), finding no clear synapomorphy supporting its validity; these families may nest separately within a paraphyletic Mesoraphidiidae (s.l.). We provide diagnoses for the families occurring at Florissant (Baissopteridae, Inocelliidae and Raphidiidae) based on wing venation.