From Fensome et al., 2019:
Protoellipsodinium spinosum Davey and Verdier, 1971, p.29–30, pl.5, fig.10. Holotype: Davey and Verdier, 1971, pl.5, fig.10. Taxonomic junior synonyms: Protoellipsodinium longispinosum and Protoellipsodinium rarispinum, both according to Heilmann-Clausen and Thomsen (1995, p.306). Age: early–late Albian.

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Locus typicus: Cotes Noires de Moeslains, France
Stratum typicum: Albian

Original description: Davey and Verdier 1971, p. 29-30
Diagnosis: Cyst elongate with sub-parallel sides. Hypotract larger than epitract. Spines numerous, only sometimes obviously aligned parallel to the cyst long axis; solid or hollow with a restricted lumen; broadly acuminate and usually less than 1/2 cyst width.
Dimensions: Range: Central body length: 37-41 µm; Central body width: 22-27 µm; Spine length: 9-12 µm.
Description: Very rarely 2 or 3 spines may be joined proximally by low crests. Distal bifurcation of a spine was observed once.

Affinities:
Davey and Verdier, 1971, p. 30
Protoellipsodinium spinosum may be distinguished from P. spinocristatum by the absence of well defined crests aligned parallel to the long axis of the cyst.

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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 spinosum Davey and Verdier, 1971. Diagnosis from Davey and Verdier (1971, p.29-30), Cyst elongate with sub-parallel sides. Hypotract larger than epitract. Spines numerous, only sometimes obviously aligned parallel to the cyst long axis; solid or hollow with a restricted lumen; broadly acuminate and usually less than ½ cyst width. Size: central body length 37-41 µm, width 22-27 µm, maximum process length 9-12 µm.
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