Back
Ceratiopsis fusiformis
Ceratiopsis fusiformis, He Chengquan, 1991, p.75, pl.34, figs.15–16.
NOW Cerodinium. Originally Ceratiopsis (generic name illegitimate), subsequently (and now) Cerodinium. Following I.C.N. Article 55.1, the species name Ceratiopsis fusiformis is validly published even though the generic name Ceratiopsis is illegitimate.
Holotype: He Chengquan, 1991, pl.34, fig.16.
Location and stratigraphy: Wuqia County Basebulak; lower Qimugen Fm, near the bottom.
Age: Paleocene.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The outline is an elongated pentagonal or spindle shaped (fusiform).
The Epicyst is large, elongated isosceles triangle, tapering towards the top, forming an apical horn, the top is sharp.
The hypocyst is inverted trapezoid, the side is slightly convex or concave, the bottom edge is nearly straight and generally parallel to the cingulum, with two antapical horns, usually unequal, tapering, distally blunt (sometimes rod-shaped or with two coarse particles); The larger antapical horn is 22-25 μm long, the smaller is 12 -17 μm long, they are far fro each other (50-62.5 μm) and spread in different directions.
The cingulum is located at the widest side of the cyst and annular, narrow, 4-5.5 μm wide, edges are marked by fine ridges.
The sulcus is limited to the lower cyst, the outline is fuzzy.
The outer wall is thin with a granular surface, the granules are diluted, the size varies, the diameter of the larger ones is about 1 μm; The wall is often wrinkled. The inner body is nearly circular with a thin and smooth wall. It is completely separated from the outer wall at the apex, antapex and lateral horns, and close to or attached to each other on the side (except at the lateral horns).
The archeopyle is big, intercalary, the outline is hexagonal or fake square, the size is about 30 × 30 μm. The operculum is off.
Dimensions:
Cyst length is around 110 μm around, width 70-80 μm, the inner body length 52-70 μm, width 67. 5-70 μm (measured 2), the positive model specimen length 110 μm, width 70 μm, inner body length 52 μm, width 67.5 μm (2 specimens measured).
Affinities/Comparison:
This species differs from Deflandrea cygniformis by elongated isosceles triangle epicyst, developed antapical horns and coarse granular outer wall. The latter has a distally extremely braided apical horn, and not developed antapical horns. This species I is also similar to Ceratiopsis subquadra in appearance, but the latter has a larger hypocyst and the wrinkled surface.
NOW Cerodinium. Originally Ceratiopsis (generic name illegitimate), subsequently (and now) Cerodinium. Following I.C.N. Article 55.1, the species name Ceratiopsis fusiformis is validly published even though the generic name Ceratiopsis is illegitimate.
Holotype: He Chengquan, 1991, pl.34, fig.16.
Location and stratigraphy: Wuqia County Basebulak; lower Qimugen Fm, near the bottom.
Age: Paleocene.
-------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------
Original description: [He Chengquan, 1991]: (translated by Suning Hou, 07-01-2019):
Description:
The outline is an elongated pentagonal or spindle shaped (fusiform).
The Epicyst is large, elongated isosceles triangle, tapering towards the top, forming an apical horn, the top is sharp.
The hypocyst is inverted trapezoid, the side is slightly convex or concave, the bottom edge is nearly straight and generally parallel to the cingulum, with two antapical horns, usually unequal, tapering, distally blunt (sometimes rod-shaped or with two coarse particles); The larger antapical horn is 22-25 μm long, the smaller is 12 -17 μm long, they are far fro each other (50-62.5 μm) and spread in different directions.
The cingulum is located at the widest side of the cyst and annular, narrow, 4-5.5 μm wide, edges are marked by fine ridges.
The sulcus is limited to the lower cyst, the outline is fuzzy.
The outer wall is thin with a granular surface, the granules are diluted, the size varies, the diameter of the larger ones is about 1 μm; The wall is often wrinkled. The inner body is nearly circular with a thin and smooth wall. It is completely separated from the outer wall at the apex, antapex and lateral horns, and close to or attached to each other on the side (except at the lateral horns).
The archeopyle is big, intercalary, the outline is hexagonal or fake square, the size is about 30 × 30 μm. The operculum is off.
Dimensions:
Cyst length is around 110 μm around, width 70-80 μm, the inner body length 52-70 μm, width 67. 5-70 μm (measured 2), the positive model specimen length 110 μm, width 70 μm, inner body length 52 μm, width 67.5 μm (2 specimens measured).
Affinities/Comparison:
This species differs from Deflandrea cygniformis by elongated isosceles triangle epicyst, developed antapical horns and coarse granular outer wall. The latter has a distally extremely braided apical horn, and not developed antapical horns. This species I is also similar to Ceratiopsis subquadra in appearance, but the latter has a larger hypocyst and the wrinkled surface.