Abstract

Libanoephemera inopinatabranchia gen. and sp. nov., an ephemeropteran nymph from the Lower Barremian dysodiles of Lebanon, is herein characterized, described, illustrated and assigned to an incertae sedis family. It differs from all known ephemeropteran nymphs and is characterized by hypognathous mouthparts, hind wing pads not covered by fore wing pads, legs with five-segmented tarsi and presence of five pairs of gills on abdominal segments; abdominal segments I and III–V with two-branched gills; segment VI bearing complex gills with six branches.