Family Dysoneuridae Sukatsheva, 1968

Type genus and species: Dysoneura trifurcata Sukatsheva, 1968.

Family diagnosis

Dysoneuridae clearly distinguished from all extant and extinct families of Trichoptera by the tibial spur formula 2/2/ 4 in combination with the following fore- and hind wing venational characters. In forewing, forks I and IV absent and forks II, III, and V present; the nygma absent; discoidal and median cells closed or open; the thyridial cell long and closed; Cu2 reaches the desclerotized line (crossvein) running from the wing margin to Cu1b. In the hind wing, forks I, III, and V are present; and forks II and IV and the discoidal cell are absent. Antennae about as long as the forewings or longer; the scapus as long as the head or longer, often bearing a brush of long dark setae.

The family Dysoneuridae belongs to superfamily Sericostomatoidea indicated by the absence of ocelli, with the terminal maxillary and labial segments being nonannulated and inflexible and the tibial spur formula being 2/2/4. The Dysoneuridae are distinct from all other families of Sericostomatoidea by their typical wing venation of fore- and hind wings.

Remarks

The family Dysoneuridae as established by Sukatsheva (1968) is based merely on the venation of an isolated forewing preserved in sedimentary rocks from the Upper Jurassic in southern Kazakhstan. The forewing venation was interpreted as a reduced venation because of the absence of apical forks I and V; in addition, Cu2 reaches a desclerotized line running from the wing margin (arculus) to Cu1b; both characteristics correspond approximately to those of the wings of the family Kokiriidae (Sukatsheva and Vassilenko, 2013). However, for a complete and significant description and classification of Trichoptera, a complete set of morphological characters is imperatively needed. In the case of the family Dysoneuridae, this became recently available by excellently preserved specimens from Cretaceous Burmese amber, subsequently leading to a redescription of the family Dysoneuridae and their assignment to the superfamily Sericostomatoidea (Wichard et al., 2018).