All known records of Middle and Late Callovian aptychi from the Russian Plate are revised. Apty- chi first figured in the 19th century by S.N. Nikitin and I.I. Lahusen are refigured and described. The re-exam- ination of the holotype Praestriaptychus kostromensis Trauth, 1930, originally identified as "Aptychus des Cos- moceras galilaei Nikitin," showed that it is an imprint of a bivalve shell (Astartidae). Aptychi figured by Lahusen (1883) and specimens from my collection are assigned to the genera Praestriaptychus and Kos- mogranulaptychus gen. nov. Relationships between the so-called smooth aptychi of the Middle Jurassic and ammonite taxa are discussed. A phylogenetic scheme for the genera Praestriaptychus, Laevaptychus, Kos- mogranulaptychus, and Granulaptychus, based on the associated occurrences of aptychi and ammonites, in the context of ammonite phylogeny is proposed. A new genus, Kosmogranulaptychus (with the type species K. call- oviensis (Trauth)), and two new species, Praestriaptychus ryasanensis and Kosmogranulaptychus lahuseni, are described.