Balkhania balkhanica Mamontova, 1966 (benthic foraminifera) and Kopetdagaria sphaerica Maslov, 1960 (dasycladalean alga) from the Lower Cretaceous Tirgan Formation of the Kopet Dagh mountain range (NE Iran) and their paleobiogeographic significance

The poorly known larger benthic foraminifer Balkhania balkhanica Mamontova is reported from the Tirgan Formation (Upper Barremian-Lower Aptian) in the northeastern part of Iran. It was so far only known from Iran (Kopet Dagh and Central Iran), Turkmenistan, and central Afghanistan. Obviously, B. balkhanica possessed a limited distributional area overlapping largely with that of the dasycladalean alga Kopetdagaria sphaerica Maslov (Turkmenistan, Iran, Georgia, Bulgaria, Romania), Conradella bakalovae (Conrad and Peyberne` s) (Tibet?, Georgia, Bulgaria, Romania), and other taxa. These taxa typify the so-called Carpatho-Pontic algal bioprovince sensu Bucur (2000), which is emended and replaced with the new name Carpatho-Cimmerian bioprovince being part of the former northern (= Eurasian) margin of the Neo-Tethys. The present case study provides a further example that the investigation of the distribution pattern of larger benthic foraminifera, together with dasycladalean green algae, may provide a useful proxy in paleotectonic and paleogeographic reconstructions of the Peri-Tethyan domain.

Benthic foraminifera  Dasycladales  Orbitolinids  Lower Cretaceous  Paleogeography  Provincialism  Endemism  Bioprovince  Cimmeria