New taxa and wing venation disparity in Vitimotauliidae (Trichoptera) from the Lower Cretaceous Yixian Formation

Vitimotauliidae, an extinct caddisfly family with the highest Mesozoic palaeobiodiversity, remains poorly represented in China, with only a few species. Herein, based on comparative morphology and geometric morphometric analyses, one new genus, Trichosukatshevia gen. nov., with two new species, T. simplex sp. nov. and T. furcivenata sp. nov., and one new species of Multimodus Sukatsheva, 1968, M. yixianensis sp. nov. are described and illustrated from the Lower Cretaceous of Yixian Formation in China. These discoveries of new taxa significantly enhance the taxonomic diversity of Vitimotauliidae. Notably, among them, Trichosukatshevia gen. nov. represents a novel lineage characterized by an open MC, a previously unreported character in the family. Moreover, morphological variations at the branching point of F4 and cross-vein m-cua are identified, expands the known morphological disparity of wing venation in Vitimotauliidae. This study highlights the evolutionary and morphological complexity of Mesozoic caddisflies, providing critical insights into their diversification during the Early Cretaceous.