Taxonomic revision on the genus Ornatomalthinus Poinar and Fanti (Coleoptera: Cantharidae), with description of a new species from the Cretaceous Burmese amber

Abstract

Ornatomalthinus ruicheni sp. nov from the Upper Cretaceous (Cenomanian, ca. 99 Ma) Burmese amber is described and illustrated; this new species can be differentiated from its congener on the basis of the following characters: rounded anterior and posterior margins of the pronotum, surface of pronotal disc smooth, elytra broad in the basal half and lineally narrowing apically. The diagnostic characters of Ornatomalthinus are discussed and redefined. Furthermore, the new placement of Ornatomalthinus in the subfamily Silinae, tribe Silini is suggested. A potential flower-visiting preference is proposed for this species on the basis of the morphological similarities to extant cantharids and flowing-visiting beetles. Our discovery highlights the diversification of early soldier beetles, which may be closely related to the rise of angiosperms during the late Mesozoic.