The synlestid damselfly, Cretaphylolestes cretacicus gen. et sp. nov., is described from the Lower Cretaceous Shouchang Formation (lower Aptian) of Zhejiang Province, Eastern China. It is the oldest Synlestidae, as we exclude the Late JurassiceEarly Cretaceous genus Gaurimacia from this family. The clade Lestiformia is currently represented in the Mesozoic by two Early Cretaceous genera of its stem group, a Perilestidae from the mid-Cretaceous Burmese amber and this newly described Synlestidae. This group remains under-represented in the Cretaceous, compared to the other zygopteran subclades. It probably diversified during the Late Cretaceous and the Paleocene, as the Lestidae are frequent and diverse in the Oligocene and more recent periods. (c) 2021 Elsevier Ltd. All rights reserved.