The present paper describes a new genus and species, Sorodites angustipes, that represents the first nitidulid found in Cretaceous Burmese amber. It is assigned to the Soronia-generic complex (subfamily Nitidulinae, tribe Nitidulini). This specimen differs from all known members of the family by its subcylindrical to cylindrical tarsomere 3 (not lobed as in most members of the family), the pro- and mesotarsi with lobed tarsomeres 1 and 2, and also from all members of the subfamily Nitidulinae by its antennal club having a weak dorsoventral compression. The exuvium described as probable Sorodites angustipes represents a first Mesozoic remains of preimaginal instar of the family Nitidulidae. The Soronia- and Phenolia-complexes are re-defined and clarified, and attribution of the genus Cacconia Sharp, 1890 to the second complex is confirmed.