Suttonium riedeli Dumitrică, 1983a

1983a Suttonium riedeli Dumitrică, p. 44, pl. 3, figs. 1, 2. non Suttonium riedeli Dumitrică in Nishimura, 2001, p. 298, pl. 2, fig. 17.

Remarks. This is the oldest described species of the genus Suttonium, based on two photos provided by Dr. W. R. Riedel. This species differs from S. anomalum (Sutton) in the relation between the microsphere and the cortical shell, the former being almost completely included in the cortical shell. It differs also in having the antapical arm inflated on the proximal part, this inflated part being separated from the central part of shell by a constriction resulted from the presence of two opposite branches of the primary antapical ray in equatorial plane.

As discussed above, the late Paleocene specimen illustrated by Nishimura (2001, p. 298, pl. 2, fig. 17) as Suttonium riedeli does not belong to this species but represents an older new species, the oldest in fact, that makes the transition between Homunculodiscus and Suttonium .

Range and occurrence. Upper Paleocene to lower Eocene; DSDP 40-11-4, 70-73 cm and DSDP 96-3-5, 42-44 cm.