A new genus of sap beetles in Cretaceous amber from northern Myanmar (Coleoptera: Nitiduloidea: Nitidulidae)

Nitidulidae is a polyphagan family with high biodiversity, wide distribution, and rich feeding habits. The richness of the tribes of the subfamily Nitidulinae, their diversity of identification characteristics, and subtle differences make it more difficult to conduct a taxonomic study of Nitidulinae in Cretaceous Burmese amber. Here we report a new genus and species of sap beetles in Burmese amber, Spinanitidula nigrumflavo Zhao & Cai gen. and sp. nov., that is clearly distinguished from all nitidulid subfamilies except Nitidulinae. We tentatively place Spinanitidula nigrumflavo gen. and sp. nov. in Nitidulinae and compare Spinanitidula in detail with representatives of all tribes in the subfamily. Furthermore, we found that, there are one row of spines on the inner and outer edges of protibiae, and four rows of spines and at least two rows of setae on meso- and metatibiae in the new species, which is different from extant nitidulids. Our discovery enriches the fossil record of Nitidulidae in mid-Cretaceous Burmese amber.