Ephemeropsis trisetalis Eichwald 1864

Taxonomy

Mayfly nymph

Kingdom: Animalia
Phylum: Arthropoda Latreille 1829
Class: Insecta Linnaeus 1758
Order: Ephemeroptera Hyatt and Arms 1890
Family: Hexagenitidae Lameere 1917
Genus: Ephemeropsis
Species: Ephemeropsis trisetalis
Author Citation Eichwald 1864

Geological Time Scale

Eon: Phanerozoic
Era: Mesozoic
Period: Cretaceous
Sub Period: None
Epoch: Early
International Age: Barremian to early Aptian

Stratigraphy

Jehol Group
Yixian Formation
Jiangshangou Bed

Provenance

Acquired by: Purchase/Trade

Dimensions

Length: 5 cm

Location

Sihetun
Chaoyang Prefecture
Liaoning Province
China

• ephemeropsis
• epicharmeropsis
• jehol group
• liaoning
• sihetun
• tff-oilshale-ar2790
• yixian formation

Comments

Taxonomy from Fossilworks.org.

The name "Jehol Biota" replaced the former "Jehol Fauna", which Amadeus William Grabau  (1923) defined as the fossil assemblage typified by numerous fossils of the  conchostracan Eosestheria, the mayfly Ephemeropsis, and the Teleost fish Lycoptera. Thus it was sometimes called "EEL".

Ephemeropsis trisetalis is a mayfly nymph described by Eichwald in 1864. the type locality is Tourga river in siberia, an Aptian lacustrine mudstone in the Turga Formation of the Russian Federation.
Some Chinese paleoentomologists attributed most of the specimens of Hexagenitidae, which are similar to Ephemeropsis from China, especially Northern China, to so-called Ephemeropsis trisetalis Eichwald 1864. Hong (1982) published a line drawing (Fig. 8C.) of imago based on a specimen from Yixian Formation, Heishangou Village, Chifeng County, Liaoning Province, China. The line drawing shows the same character of new genus Epicharmeropsis: distinct intercary veins existing between MP1 and CuA1 which is obviously different from Ephemeropsis although the drawing itself had  (according to Huang et al. 2007) some mistakes.
Huang, et al. 2007 are of the opinion that the species of Ephemeropsis, which only occurred in Transbaikalia of Russia and Mongolia, was not present in China. The Ephemeropsis-like imago specimens reported before from China, which was classified as Ephemeropsis trisetalis, should be placed into the new genus Epicharmeropsis. Of course, as the nymph specimens of Hexagenitidae from China have not been described in detail and the association between nymphs and adults has not been established, their opinion should be considered as preliminary.
References:
Eichwald, E. (1864). Sur un terrain jurassique à poissons et insectes d'eau douce de la Sibérie orientale. Bulletin de la Société Géologique de France, Deuxième Série 21:19-25.

Hong, Y. C. (1982). Mesozoic Fossil Insects of Jiuquan Basin in Gansu Province. Geological Publishing House, Beijing, 210 pp.

Huang, J., Ren, D., Sinitshenkova N. D. & Shih, C. (2007). New genus and species of Hexagenitidae (Insecta: Ephemeroptera) from Yixian Formation, China. Zootaxa 1629: 39–50.