Abstract
The morphology of the middle ear was examined in all recent glirid genera except Chaetocauda. The evolutionary transformatian of auditory bul la in this group is interconnected with pneumatization of its tympanic and mastoid regions. Several pathways of the middle ear specialization in glirids was recognized. The scheme of interrelations between different groups within family Gliridae showing morphological diversity of the dormice middle ear morphology is presented. Glirulus stands far apart from Glis. The Muscardinus also represents independent line that seems to be more closely related to the Dryomys-Eliomys phylum than to Glis. Among graphiurins, independent position can be asserted to each of G.(Aethglis) lıueti and G.(Claviglis) crassicaudutus. Close affinity of Selevinia to Myomimus, and of Dryomys to Eliomys are also argued.