We studied phenotypic relationships among six European Apodemus species (A. agrarius, A. epimelas, A. flavicollis, A. sylvaticus, A. uralensis, and A. alpicola) using landmark based morphometrics. Cartesian coordinates of 14 landmarks were recorded on the occlusal projection of upper molars from 175 specimens. Results revealed A. agrarius as the most distinct, having long and slender molars. Since primitive members of the genus (A. atavus, A. orientalis, A. dominans) are characterised by broad and robust molars, we conclude that A. agrarius is the most derived in this respect. Within the Sylvaemus subgenus/species group A. epimelas differed from the remaining four species in having more robust molars and a relatively longer second molar. Within the remaining four species two clusters emerged, although differences between them were slight. The flavicollis-sylvaticus tandem exhibited a relatively shorter second molar and more robust first molar. In five Sylvaemus, the robustness of molars correlated negatively with molar size, suggesting that between-species differences in molar shape result from allometric relations.
The Poecilimon ornatus group has an exclusively European distribution and includes the largest species in the genus. A revision of the taxa belonging to this group in Bulgaria and Macedonia (Central and Eastern Balkan Peninsula) is presented. Nine taxa described from Bulgaria are synonymised with 3 previously known species, as follows: Poecilimon ornatus (= P. mistshenkoi marzani, syn. n., P. mistshenkoi tinkae, syn. n., P. mistshenkoi vlachinensis, syn. n.), P. affinis s. str. (= P. mistshenkoi mistshenkoi, syn. n., P. affinis ruenensis, syn. n., P. affinis rilensis, syn. n., P. affinis medimontanus, syn. n., P. harzi, syn. n.) and P. hoelzeli (= P. kisi, syn. n.). The synonymy of P. poecilus with P. affinis and the subspecific status of P. affinis komareki are confirmed. One species, Poecilimon jablanicensis, sp. n., is described as new to science. A tabulated key, lists and maps of all known localities and oscillograms of the songs of all the species in this group are presented. The phylogenetic relationships and evolutionary trends in the Poecilimon ornatus group are discussed.