Buchanosteids (Placodermi, Arthrodira) from Central Asia

Remains of two buchanosteids from the Early Devonian of Central Asia, Kazakhstan and Uzbekistan, are described. The skull-roof of Buchanosteus nuricus n. sp. comes from the Qaraghandy region, Kazakhstan. The Zinzilban Gorge section, Uzbekistan has also yielded a suborbital plate, belonging to Buchanosteus sp. Buchanosteids are very widely distributed Early Devonian brachythoracids. They were initially described from eastern Gondwana (Australia), but are now also known from China, western Gondwana (Iran, Saudi Arabia), Kazakhstan, the southern and western Siberian + Kara-Tajmyr Continents (Uzbekistan, Siberian Arctic) and the eastern part of Euramerica (Spitsbergen, South Urals). The buchanosteids from Central Asia are fairly similar to the type species, Buchanosteus confertituberculatus (CHAPMAN), and indicate some connection between the Emsian paleobasins