New data on some type species of Maastrichtian - Paleocene Dasycladales (Green algae) from Iran, Part 2 Hamulusella Elliott in Deloffre and Granier 1992

Abstract

Hamulusella sedalanensis represents the type species of the genus Hamulusella Elliott described from the Paleocene of Iraq (type locality) and Iran. Well preserved material from the Paleocene of Iran (East Iran, and Zagros Zone, SWIran), allows a better characterisation of the algal thallus including its ranges of biometric parameters. The thallus of H. sedalanensis consists of superimposed articles each composed of two verticils. This leads to characteristic biverticilate articles after disintegration. This thallus organization challenges the taxonomic status of the Lower Cretaceous H. durandelgai (Fourcade and Jaffrezo), and H. liburnica (Radoicic). The latter is transferred to the genus Aloisalthella Granier due to the alternation of fertile and sterile whorls thus excluding its belonging either to Clypeina Michelin or Hamulusella Elliott. The occurrence of larger benthic foraminifera (LBF) allows the dating of the Iranian specimens to the Selandian–Thanetian. The occurrence of H. sedalanensis in Eocene strata has so far not reliably been evidenced. Among the associated LBF, taxonomic notes on Azzarolina daviesi (Henson) are provided.