Estiastra? oligospinosa (Eisenack, 1934 ex Eisenack, 1938) Jacobson and Achab, 1985
Acritarch

Originally Hystrichosphaeridium oligospinosum, subsequently Pulvinosphaeridium oligospinosum (an acritarch species), thirdly Veryhachium oligospinosum (an acritarch species), fourthly Goniosphaeridium oligospinosum (an acritarch species), fifthly (and now) Estiastra? oligospinosum; see also Ovum hispidum ssp. oligospinosum (name not validly published). Jacobson and Achab, 1985 questionably included this species in Estiastra.
Holotype: Eisenack, 1934, pl.4, fig.18; lost, according to Eisenack et al., 1973
Age: Silurian (based on material from an erratic)