Four specimens of fossil beetles recorded from the Middle and Late Jurassic boundary beds of Inner Mongolia, China are assigned to the melyrid lineage of Cleroidea. Three of them are described as Sinomelyris praedecessor gen. et sp. nov. and constitute the earliest known representatives of the family Melyridae. The new species habitually resembles some extant beetles of the subfamily Melyrinae but it is distinctly smaller and possesses four elytral carinae, the pronotum without a pair of the dorsolateral carinae, and the tarsal claw simple. The fourth specimen Juraniscus majeri gen. et sp. nov., is classified as Cleroidea incertae sedis. The new species has the symmetrical antennomeres including three terminal ones, the tarsomeres 1-4 with the lobes, the tarsal claw simple, and the aedeagus with the separated parameres. It is considered to be a member of the melyrid lineage and its relations to the relevant families Mauroniscidae, Rhadalidae, Dasytidae, and Malachiidae are discussed. A complete list of fossil species in the melyrid lineage described to date is provided.