Pareodinia ?spinosissima (Deflandre, 1939a, p.179, pl.9, fig.11 ex Deflandre and Cookson, 1955, p.258) Wiggins, 1975, p.107. Holotype: Deflandre, 1939a, pl.9, fig.11. Originally Palaeoperidinium (name not validly published), subsequently Palaeohystrichophora, thirdly Acanthaulax?, fourthly Pareodinia, fifthly (and now) Pareodinia?. Questionable assignment: Stover and Evitt (1978, p.117) and Below (1990, p.66) as a "nomen dubium". The name Palaeoperidinium spinosissimum was not validly published in Deflandre (1939a) since the generic name Palaeoperidinium was not validly published until 1967. Age: Late Jurassic.