Odonatans in lowermost Cenomanian Kachin amber: updated review and a new hemiphlebiid damselfly

Abstract

Odonatans are rare in Cretaceous amber deposits, and only four fragmentary specimens were recorded in Lebanese, Jordanian, Charentes and South Dakota ambers except for Kachin amber. This study reviewed the odonatans in lowermost Cenomanian Kachin amber and commented 11 odonatans, which were previously placed in the family level. Until now, over 350 odonatans have been found in Kachin amber, including 38 species of three extant suborders, and representing the most diverse and abundant dragonfly assemblage in amber inclusions. The dominated odonatans include the damselflies Burmahemiphlebia zhangi and Mesomegaloprepus magnificus, and the damsel-dragonfly Burmaphlebia reifi, accounting for ca. 79% of all odonatans. The Kachin odonatans include the earliest records of the damselfly Perilestidae, Platycnemididae and Platystictidae, and the youngest records of the true dragonfly Araripegomphidae and Stenophlebiidae, contributing to exploring the origination and evolution of these families.Hemiphlebiidae is the dominant family in Kachin amber, represented by the species Burmahemiphlebia zhangi with ca. 160 species been recorded. It is surprising that the hemiphlebiid damselfly is abundant, but the diversity is very low with only two species been previously reported. Herein, a new hemiphlebiid damselfly, Kachinhemiphlebia lini gen. et sp. nov., is described by the unique characters: Arc slightly distal of Ax2 in both fore- and hindwings; and a well-defined AA ending on posterior wing margin below Ax2. This is the second genus of the Hemiphlebiidae in Kachin amber.