The division of mayflies into two main phylogenetic branches, Posteritorna and Anteritorna, is now traced up to the Triassic. The earliest known representative of Anteritorna is the Triassic Hammephemera pulchra Sinitshenkova (in Bashkuev et al.) 2012, for which a new family Hammephemeridae fam. n. is established. Reliable Jurassic representatives of Posteritorna are Jurassephemera zhangi Zhang et al. 2022 and Sharephemera cubitalis Sinitshenkova, 2002. The Triassic Tunephemera tungussica Sinitshenkova, 2013 is placed in Posteritorna presumably. urn:lsid:zoobank.org:pub:825122F8-D6B6-419D-980A-FDB0B6AC5F29.