Baltisphaeridium fimbriatum, (White, 1842), Downie and Sarjeant, 1965

Now Comasphaeridium (an acritarch genus). Originally Xanthidium (an extant desmid genus), subsequently Hystrichosphaeridium, thirdly Baltisphaeridium, fourthly (and now) Comasphaeridium (an acritarch genus). This combination was not validly published in Sarjeant, 1959 and Downie and Sarjeant, 1963 since these authors did not fully reference the basionym.

Holotype: White, 1842, pl.4, div.3, fig.3; Sarjeant, 1991, fig.4.2
Age: Late Cretaceous