Occisucysta thulia Davies, 1983

Now Ctenidodinium?. Originally Occisucysta, subsequently (and now) Ctenidodinium?.
Holotype: Davies, 1983, pl.5, figs.10-11
Locus typicus: Eastern Cornwall Island, Northwest Territories, Canada
Stratum typicum: Middle Callovian-Oxfordian

Original diagnosis: Davies, 1983, p. 19
A large oblate species of Occisucysta marked by denticulate crests and penitabular hair-like spines. Tabulation: "?4". ?a, 6", 6c, ?""",?"""". Archeopyle: P(3). Size: length- 83(89)94 µm; breadth - 80(92)112 µm.

Original description: Davies, 1983, p. 19
The hair-like spines (2-5 µm long) arise in penitabular bands around the periphery of the plates leaving the centre of the plates less ornamented. The sutural crests are 8 µm high. The cyst is usually polarly compressed and is oval in outline. When ventrally compressed it has a rounded pentagonal outline with little or no apical horn development. It is often split epitractally.

Affinities:
Davies, 1983, p. 20: The large size, the denticulate crests and the hair like spines distinguish it from all other species of Occisucysta.