Adnatosphaeridium filamentosum

"filamentosum" (Cookson and Eisenack, 1958, p.47–48, pl.7, figs.8–9; pl.8, figs.1–2) Williams and Downie, 1969, p.17.  Holotype: Cookson and Eisenack, 1958, pl.7, fig.9.  NOW Rigaudella.  Originally Cannosphaeropsis, subsequently Adnatosphaeridium, thirdly (and now) Rigaudella.  Taxonomic junior synonym: Cannosphaeropsis perforata, according to Stancliffe and Sarjeant (1990, p.206).  This combination was not validly published in Williams and Downie (1966c, p.218), since these authors did not fully reference the basionym.  Age: Middle-Late Jurassic.

Parent: Adnatosphaeridium