Heptageniidae

The Heptageniidae (synonym: Ecdyonuridae) are a family of mayflies with over 500 described species mainly distributed in the Holarctic, Oriental, and Afrotropical regions, and also present in the Central American Tropics and extreme northern South America.[1] These are generally rather small mayflies with three long tails. The wings are usually clear with prominent venation although species with variegated wings are known. As in most mayflies, the males have large compound eyes, but not divided into upper and lower parts (the group is sometimes referred to as flat-headed mayflies).

Heptageniidae Temporal range: Turonian–Present PreꞒ Ꞓ O S D C P T J K Pg N
Rhithrogena germanica
Scientific classification
Kingdom:	Animalia
Phylum:	Arthropoda
Class:	Insecta
Order:	Ephemeroptera
Suborder:	Schistonota
Superfamily:	Heptagenioidea
Family:	Heptageniidae
Genera include
Acanthomola Afghanurus Afronurus Anepeorus Cinygma Cinygmula Darthus Ecdyonurus Electrogena Epeorus Heptagenia Ironodes Kageronia Leucrocuta Macdunnoa Nixe Parafronurus Raptoheptagenia Rhithrogena Stenacron Stenonema

Heptageniids breed mainly in fast-flowing streams (an alternative common name is stream mayflies), but some species use still waters. The nymphs have a flattened shape and are usually dark in colour. They use a wide range of food sources with herbivorous, scavenging, and predatory species known.

The oldest described member of the family is Amerogenia from the Turonian aged New Jersey amber.