New Blattarians and a Review of Dictyopteran Assemblages from the Lower Cretaceous of Mongolia

Dictyopteran assemblages (cockroaches, mantises and termites) from Mongolia were uniform, being composed of the same genera throughout the Early Cretaceous (more than 30 million years), corresponding to the “dry and warm Baissa type” assemblages from Siberia. The assemblage from Shin-Khuduk is exceptional, consisting of a single identifiable blattulid species, Vrtula soma gen. et sp. nov. Assemblages from Eastern Erdenyi-Ula, Khurilt, Kholbotu-Gol, and Shar-Tologoy are composed of species already known from the richest Lower Cretaceous locality Bon Tsagaan, but species representation in the various assemblages differs considerably. Nuurcala srneci sp. nov. from Khurilt Bed 210/24, with a forewing length under 12 mm, is the smallest and best-studied example of the cosmopolitan Mesozoic family Caloblattinidae. The last occurrence of the predominantly Palaeozoic family Phyloblattidae is reported from Bon Tsagaan.