The Mayflies (Ephemeroptera) - order
over 400 genera in 42 families
(Pannota) - suborder
(Ephemerelloidea) - superfamily

(Ephemerellidae)
- family

(Leptohyphidae)
- family

(Tricorythidae)
- family
(Caenoidea) - superfamily

(Neoephemeridae)
- family

(Baetiscidae)
- family

(Caenidae)
- family

(Prosopistomatidae)
- family
(Schistonota) - suborder
(Baetoidea) - superfamily

(Siphlonuridae)
- family

(Baetidae)
- family

(Oniscigastridae)
- family

(Ameletopsidae)
- family

(Ametropodidae)
- family
(Heptagenioidea) - superfamily

(Coloburiscidae)
- family

(Oligoneuriidae)
- family

(Isonychiidae)
- family

(Heptageniidae)
- family
(Leptophlebioidea) - superfamily

(Leptophlebiidae)
- family
(Ephemeroidea) - superfamily

(Behningiidae)
- family

(Potamanthidae)
- family

(Euthyplociidae)
- family

(Polymitarcydae)
- family

(Ephemeridae)
- family

(Palingeniidae)
- family