Three new archisargid species referred to one new genus, Flagellisargus sinicus, F. venustus and F. robustus, are described based on three impressions from the Callovian–Oxfordian of the “Daohugou Formation” in Daohugou, Chifeng, Inner Mongolia, China. The presence of an elongated flagellum and large male genitalia places these new findings with the distinct but rare archisargid flies. The systematic position of Origoasilus pingquanensis Zhang et al., 2011 is reassessed, placing it with Archisargidae within Archisargoidea rather than Asiloidea. The Origoasilidae is a junior synonym for Archisargidae.