TAXONOMIC AND BIOSTRATIGRAPHIC REMARKS ON TORINOSUELLA MAYNC, 1959 AND BALKHANIA MAMONTOVA, 1966, LARGER BENTHIC FORAMINIFERA FROM THE LOWER CRETACEOUS OF IRAN (SANGESTAN, TIRGAN FORMATIONS)

Abstract

The monospecific genera Torinosuella Maync [type-species T. peneropliformis (Yabe & Hanzawa)] and Balkhania Mamontova (type-species B. balkhanica Mamontova) have been reported from the Lower Cretaceous of Iran, respectively the ‘Carbonate Member’ of the Sangestan Formation (Central Iran) and the Tirgan Formation (NE Iran). The literature review reveals a range of late? Tithonian–early Barremian for Torinosuella and late Barremian–early Aptian for Balkhania. In a recent publication dealing with the ‘Taft’ Formation (Central Iran) and the Tirgan Formation (northeastern Iran), both taxa have been lumped together and described as two morphotypes of B. balkhanica based essentially on size differences. This mixing was associated with incorrect phylogenetic, taxonomic, biostratigraphic (e.g., First Appearance Datum) and palaeoecological conclusions that are herein addressed and corrected. Without clarification about the spatial and temporal distribution of individual taxa, the usefulness of larger benthic foraminifera for biostratigraphy, palaeoecology and palaeobiogeography would be distinctly reduced.