(Panephemeroptera Euephemeroptera Euplectoptera Anteritorna Bidentiseta Furcatergaliae  
Tricorythus/fg1Ephemerella/fg2 Timpanoga/fg1 - Timpanoga/fg2)

Nomen hierarchicum:  Timpanoga/fg2 [f:1984; g:1927] (sine Attenella; incl. Eurylophella)

In circumscription fits:

— Timpanoga/fg2: Kluge 2004: 301

References. McCafferty & Wang 1994a ("Eurylophella – Dentatella – Timpanoga – Dannella" lineage): *; – Kluge 2004: * * * *

Autapomorphy of Timpanoga/fg2.

(1) Tergalii are more or less operculate: Tergalius IV [the anteriormost among lamellate tergalii – see Timpanoga/fg1 (1)] is enlarged, covers not less than 1/2 of tergalius V. Abdominal segments bearing tergalii have enlarged lateral lobes: at least on each of abdominal segments V–VII posterolateral process is longer than segment in its middle part (Kluge 2004: Fig.91:I).

Plesiomorphy of Timpanoga/fg2. Unlike Attenella, distal segment of gonostylus is not elongate.

Size. Fore wing length 6–14 mm.

Distribution. Mainly Nearctic, also in Europe.

The taxon Timpanoga/fg2 is divided into:

1. Eurylophella/fg1

1.1. plesiomorphon Dentatella

1.2. Eurylophella/fg2

2. Timpanoga/fg3
2.1. plesiomorphon Dannella

2.2. Timpanoga/fg4