A new caddisfly of the family Baissoferidae (Insecta: Trichoptera) from the Lower Cretaceous of Mongolia

Abstract

This article is devoted to the description of a new representative of the family Baissoferidae from the Khutel-Khara locality (Mongolia, East Gobi Aimag) located 75 km southwest of Mount Sain-Shand. The insect-bearing deposits of the Tsagan Tsab Formation, the Lower Tsagan Tsab Subformation in this locality are dated to the earliest Cretaceous, Berriasian-Valanginian. In total, about 3,300 fossil insect imprints of 14 orders were collected from the Khutel-Khara locality. It is important that the fauna of insects has both Jurassic and Cretaceous features. For example, many mayfly and stonefly nymphs that lived there (Sinitshenkova, 1987, 1989) were still typical Jurassic lacustrine forms, while among terrestrial insects, on the contrary, forms that occur mainly in the Lower Cretaceous of Transbaikalia (some rove beetles and scarabaeoids) prevailed (Ponomarenko, 2021). It is especially interesting that many forms are represented in Khutel-Khara, first appearing in the geological record, then widespread in the Lower Cretaceous. This primarily concerns hymenopteran insects (Rasnitsyn, 1990; Kopylov & Rasnitsyn, 2020).