Fig. 4 in Developing Best Practice In Micropalaeontology: Examples From The Mid-Cretaceous Of The Zagros Mountains

Fig. 4 Morphological variability (apical angle, test height and diameter) of the late Aptian – middle Albian Mesorbitolina texana (Roemer). a late Aptian Taft Formation of Central Iran. b late Aptian of Lebanon (from Schroeder and Neumann, 1985, pl. 36, fig. 2, topotype of Orbitolina discoidea var. libanica Henson; coll. F.R.S. Henson). Also note the convex test base in a and the central depression in b with a few final annular chambers.