Scriniodinium barremianum Duxbury, 2001, p.112-113, fig.12, nos.1-2. Holotype: Duxbury, 2001, fig.12, no.1. Age: Late Barremian (holotype caved into Mid Barremian according to Duxbury, 2001, p.112).

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Original description (Duxbury, 2001):

Scriniodinium barremianum n. sp.

Holotype: Figure 12.1.
Type Locality: Well 13/24-1 at 4980 ft (ditch cuttings), Middle Barremian (caved), E.F. G41.4.
Derivation of Name: From the Barremian - this species is restricted to that Stage.

Diagnosis: A large, elongate species of Scriniodinium with a smooth to very finely granular, ovoidal endocyst, bearing a very low apical protrusion. The delicate, smooth pericyst is separated from the endocyst but with minimal cavation; the maximum separation observed is in the ventral and cingular areas and at the apices. A long, hollow, tapering and open-ended apical horn is consistently observed, formed entirely by the pericyst. The distal portion of the apical horn is invariably perforate. The archeopyle is single paraplate precingular (3").

Dimensions: Holotype: 110 × 89 μm
Overall: 120 (110) 100 × 100 (86) 76 μm
Specimens Measured - 12

Comments: Scriniodinium barremianum n. sp. is a large, distinctive species, although it is similar in some respects to Scriniodinium hauterivianum. It differs from S. hauterivianum in being significantly less cavate, and in possessing a long, distally perforate apical horn. This species is restricted to the Late Barremian, where it is a valuable stratigraphic marker species. Its extinction level near the top of the Late Barremian corresponds to the highest occurrence of Cribroperidiniumn cornutum DAVEY, 1974; in its overall size, shape and cavation, S. barremianum DUXBURY n. Sp. bears some resemblance to the last species.