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Ovoidinium verrucosum ssp. verrucosum
Ovoidinium verrucosum ssp. verrucosum
Autonym
Originally (and now) Ovoidinium verrucosum ssp. verrucosum, subsequently Ascodinium verrucosum ssp. verrucosum.
Holotype: Cooksonand Hughes, 1964, pl.5, fig.4
Locus typicus: Barrington, Cambridgeshire, England
Stratum typicum: Cenomanian
Original description: Cookson and Hughes 1964, p. 41: Ascodinium verrucosum
Diagnosis: Shell slightly longer than broad with strongly convex sides, a circular girdle and a short longitudinal furrow in the hypotheca. Shell-membrane completely adherent to the thicker wall of the capsule except at the extreme apex where it narrows towards a small, pointed, cap-like projection and antapically where it forms a prominent projection with a slanting asymmetrical base. The surface of the shell-embrane is ornamented with more or less densely arranged hollow verrucae; the wall of the capsule is unornamented, the two membranes together measure about 2-3 Ám. Opening is effected by the complete detachment of the apical portion of the shell and capsule.
Dimensions: Range: 55-80 Ám long; 40-59 Ám broad.
Comment: Considerable variation both in size of shell and density of ornament has been observed amongst the individuals included A.verrucosum, the larger shells having fewer and more widely spaced verrucae than the smaller ones.
Davey 1970, p. 351-352.
The specimens examined strongly resemble the type material from the basal Cenomanian of England. The inner body is thick-walled (c. 2µ), finely granular and possess a distinct cingulum. The periphragm membrane bears numerous large tubercles and forms a distinct sulcus confined mainly to the hypotract. At the antapex this membrane is typically extended into a single horn, asymmetrically placed, and at the apex gives rise to a small horn. The operculum occasionally remains attached. The specimens from Compton Bay are more symmetrical antapically, have a less well defined cingulum and fewer tubercles than the Fetcham Mills examples. The tubercles are sometimes in the form of small truncated processes.
Dimensions: overall length: 60-61 Ám (2 complete specimens); shell length (operculum missing): 43-58 Ám; length of inner body 32-42 Ám; width of inner body: 34-53 Ám. Number of specimens measured: 10.
Affinities:
Davey 1970, p. 351-352
Ovoidinium verrucosum may be distinguished from O.scabrosum (Cookson and Hughes 1964) by the surface ornamentation, shape of hypotract and distinct cingulum.
Autonym
Originally (and now) Ovoidinium verrucosum ssp. verrucosum, subsequently Ascodinium verrucosum ssp. verrucosum.
Holotype: Cooksonand Hughes, 1964, pl.5, fig.4
Locus typicus: Barrington, Cambridgeshire, England
Stratum typicum: Cenomanian
Original description: Cookson and Hughes 1964, p. 41: Ascodinium verrucosum
Diagnosis: Shell slightly longer than broad with strongly convex sides, a circular girdle and a short longitudinal furrow in the hypotheca. Shell-membrane completely adherent to the thicker wall of the capsule except at the extreme apex where it narrows towards a small, pointed, cap-like projection and antapically where it forms a prominent projection with a slanting asymmetrical base. The surface of the shell-embrane is ornamented with more or less densely arranged hollow verrucae; the wall of the capsule is unornamented, the two membranes together measure about 2-3 Ám. Opening is effected by the complete detachment of the apical portion of the shell and capsule.
Dimensions: Range: 55-80 Ám long; 40-59 Ám broad.
Comment: Considerable variation both in size of shell and density of ornament has been observed amongst the individuals included A.verrucosum, the larger shells having fewer and more widely spaced verrucae than the smaller ones.
Davey 1970, p. 351-352.
The specimens examined strongly resemble the type material from the basal Cenomanian of England. The inner body is thick-walled (c. 2µ), finely granular and possess a distinct cingulum. The periphragm membrane bears numerous large tubercles and forms a distinct sulcus confined mainly to the hypotract. At the antapex this membrane is typically extended into a single horn, asymmetrically placed, and at the apex gives rise to a small horn. The operculum occasionally remains attached. The specimens from Compton Bay are more symmetrical antapically, have a less well defined cingulum and fewer tubercles than the Fetcham Mills examples. The tubercles are sometimes in the form of small truncated processes.
Dimensions: overall length: 60-61 Ám (2 complete specimens); shell length (operculum missing): 43-58 Ám; length of inner body 32-42 Ám; width of inner body: 34-53 Ám. Number of specimens measured: 10.
Affinities:
Davey 1970, p. 351-352
Ovoidinium verrucosum may be distinguished from O.scabrosum (Cookson and Hughes 1964) by the surface ornamentation, shape of hypotract and distinct cingulum.