Crested antiarch Bothriolepis zadonica H.D.Obrucheva from the Lower Famennian of Central European Russia

New materials on the bothriolepidid Bothriolepis zadonica H.D. Obrucheva, 1983 from the Zadonskian Regional Stage (Upper Devonian, Lower Famennian) of Central Devonian Field (Central European Russia) are described and illustrated. These materials came from nine localities in the Orel and Tver Regions of Russia. This species is characterised by the presence of a well developed median dorsal crest in the trunk armour and unusual type of the preorbital recess of the head shield; this recess is designated herein “trapezoid”. The ontogenetic and individual variations of B. zadonica are studied. The crested bothriolepidids are known only from Euramerica and East Gondwana. The possible relationships between crested bothriolepidids in these provinces are discussed