Cleistosphaeridium ambiguum, (Deflandre, 1937), Jiabo, 1978

NOW Sepispinula?. Originally Micrhystridium (Appendix A), subsequently Cleistosphaeridium, thirdly Polysphaeridium, fourthly Chlamydophorella, fifthly Dapsilidinium, sixthly Gorgonisphaeridium (Appendix A), seventhly (and now) Sepispinula?.
Taxonomic junior synonyms: Hystrichosphaeridium (now Sepispinula?) huguoniotii, according to Clarke and Verdier (1967, p.54) and Hystrichosphaeridium (now Sepispinula) ancoriferum, both according to Yun Hyesu (1981, p.44) and Schiøler and Wilson (1998, p.328) - however, Masure in Fauconnier and Masure (2004, p.499-500) retained Sepispinula ancorifera and Sepispinula? huguoniotii.

Holotype: Deflandre, 1937, pl.16 [al. pl.13], fig.8
Age: Late Cretaceous