New fossil taxa and notes on the Mesozoic evolution of Liadytidae and Dytiscidae (Coleoptera).

The diagnoses of Liadytidae Ponomarenko, 1977, Liadytiscinae Prokin & Ren, 2010, Liadytiscus Prokin & Ren, 2010 and Mesoderus Prokin & Ren, 2010 (Dytiscidae) are modified, and the following new taxa are described from Mesozoic fossils: Liadytes aspidytoides sp. n. (Liadytidae); Mesoderini trib.