Hystrichosphaeridium oligospinosum Eisenack, 1934 ex Eisenack, 1938

Now Estiastra? oligospinosa. Originally Hystrichosphaeridium oligospinosum, subsequently Pulvinosphaeridium oligospinosum, thirdly Veryhachium oligospinosum, fourthly Goniosphaeridium oligospinosum, fifthly (and now) Estiastra? oligospinosa. See also Ovum hispidum ssp. oligospinosum (combination not validly published).
Holotype: Eisenack, 1934, pl.4, fig.18 (lost according to Eisenack et al., 1973
Age: Silurian (based on material from an erratic)