The oldest known larvae of Megaloptera (Insecta) from the Triassic of Ukraine

Abstract

The oldest unquestionable fishfly, Izyumochauliodes aristovi gen. et sp. nov. (Corydalidae, Chauliodinae), is described based on several larval fossils from the Upper Triassic Garazhovka locality in eastern Ukraine (Seversky Donets River basin, Kharkiv Region). The new genus with a typical Chauliodinae structure of the abdomen is distinguished from all other genera of the subfamily by having the occipital suture ventrally directed forward along the gula and reaching the submentum, and by the shape of mandibula with evenly curved inner margin, both characters similar to Sialidae. Another, poorly preserved larva, found in the same locality, is attributed to Sialidae incertae sedis and also represents the oldest record of the family. The co-occurrence of fossil larvae of both known families in the same locality is the palaeontological evidence for the Triassic divergence of the extant megalopteran lineages.