Baltisphaeridium claviferum Appendix A

claviferum (Wilkinson, 1849, p.89-92, pl.13, fig.1) Downie and Sarjeant, 1965, p.88.  Holotype: Wilkinson, 1849, pl.13, fig.1.  Originally Xanthidium (Appendix A), subsequently Hystrichosphaeridium, thirdly (and now) Baltisphaeridium.  According to Wilkinson (1849, p.89), "This species was originally named Xanthidium tubiferum dilatatum, but as the duplex trivial name is contrary to the rules of nomenclature, it has been thought advisable to alter it to Xanthidium claviferum ...".  Wilkinson's contention is not necessarily the case since, as Xanthidium tubiferum var. dilatatum, the "earlier" name may have been validated.  However, Wilkinson gave no further information regarding the source of the name "Xanthidium tubiferum dilatatum".  This combination was not validly published in Downie and Sarjeant (1963, p.91), since these authors did not fully reference the basionym.  Age: Late Cretaceous.

Parent: Baltisphaeridium