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Protoellipsodinium spinocristatum
Protoellipsodinium spinocristatum Davey and Verdier, 1971
Holotype: davey and Verdier, 1971, pl.5, fig.2
Locus typicus: Cotes Noires de Moeslains, France
Stratum typicum: Albian
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G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Protoellipsodinium spinocristatum Davey and Verdier, 1971. Diagnosis from Davey and Verdier (1971, p.28-29). Cyst markedly elongate with sub-parallel sides. Hypotract larger than epitract. Cingulum sometimes discernable. Spines numerous, mainly acuminate, less than 1/3rd cyst width, solid or hollow; they arise from low, interrupted crests which typically run along the length of the cyst. Cross connecting crests occasionally present. Size: central body length 37-46 µm, width 19-30 µm, maximum process length 5-11 µm.
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Original description: Davey and Verdier 1971, p.28-29
Diagnosis: Cyst markedly elongate with sub-parallel sides. Hypotract larger than epitract. Cingulum sometimes discernible. Spines numerous, mainly acuminate, less than 1/3 cyst width, solid or hollow; they arise from low, interrupted crests which typically run along the length of the cyst. Cross connecting occasionally present.
Dimensions: Holotype: central body length 37 µm, central body width 19 µm, maximum spine length 6 µm. Range: central body length 37(40.6)46 µm, central body width 19(23.4)30 µm, maximum spine length 5(9.5)11 µm.
Description: The crests, 1 to 2 µm in height, are only occasionally interrupted along their length. However, there is usually in the cingular region a paucity of crests. Cross connectioning and anastomosing crests are rare. Since the spines arise from the crests, they are similarly aligned parallel to the cyst long axis. The spines may be solid or hollow; when the latter, the lumen is somewhat restricted. they are typically acuminate but may also be blunted distally; the majority are rigid, however, fineer ones sometimes occur and these tend to be flexuous. A precingular archaeopyle, of normal shape, is always present.
Affinities:
Davey and Verdier 1971, p. 29
P. spinocristatum is easily distinguished from Ellipsodinium rugulosum by the presence of long spines and its more elongate shape. However, one specimen (Ellipsodinium sp. Davey and Verdier 1971, pl.5, fig.8) of similar appearance, but devoid of spines, was found and is considered to be an intermediary form between the above two species. It is probable that E. rugulosum evolved from P. spinocristatum by the loss of spines and a shortening of the hypotract.
Holotype: davey and Verdier, 1971, pl.5, fig.2
Locus typicus: Cotes Noires de Moeslains, France
Stratum typicum: Albian
--------------------------------------------------
G.L. Williams short notes on species, Mesozoic-Cenozoic dinocyst course, Urbino, Italy, May 17-22, 1999 - LPP VIEWER CD-ROM 99.5.
Protoellipsodinium spinocristatum Davey and Verdier, 1971. Diagnosis from Davey and Verdier (1971, p.28-29). Cyst markedly elongate with sub-parallel sides. Hypotract larger than epitract. Cingulum sometimes discernable. Spines numerous, mainly acuminate, less than 1/3rd cyst width, solid or hollow; they arise from low, interrupted crests which typically run along the length of the cyst. Cross connecting crests occasionally present. Size: central body length 37-46 µm, width 19-30 µm, maximum process length 5-11 µm.
--------------------------------------------------
Original description: Davey and Verdier 1971, p.28-29
Diagnosis: Cyst markedly elongate with sub-parallel sides. Hypotract larger than epitract. Cingulum sometimes discernible. Spines numerous, mainly acuminate, less than 1/3 cyst width, solid or hollow; they arise from low, interrupted crests which typically run along the length of the cyst. Cross connecting occasionally present.
Dimensions: Holotype: central body length 37 µm, central body width 19 µm, maximum spine length 6 µm. Range: central body length 37(40.6)46 µm, central body width 19(23.4)30 µm, maximum spine length 5(9.5)11 µm.
Description: The crests, 1 to 2 µm in height, are only occasionally interrupted along their length. However, there is usually in the cingular region a paucity of crests. Cross connectioning and anastomosing crests are rare. Since the spines arise from the crests, they are similarly aligned parallel to the cyst long axis. The spines may be solid or hollow; when the latter, the lumen is somewhat restricted. they are typically acuminate but may also be blunted distally; the majority are rigid, however, fineer ones sometimes occur and these tend to be flexuous. A precingular archaeopyle, of normal shape, is always present.
Affinities:
Davey and Verdier 1971, p. 29
P. spinocristatum is easily distinguished from Ellipsodinium rugulosum by the presence of long spines and its more elongate shape. However, one specimen (Ellipsodinium sp. Davey and Verdier 1971, pl.5, fig.8) of similar appearance, but devoid of spines, was found and is considered to be an intermediary form between the above two species. It is probable that E. rugulosum evolved from P. spinocristatum by the loss of spines and a shortening of the hypotract.