Xanthidium claviferum Wilkinson, 1849

Now Baltisphaeridium (an acritarch genus). Originally Xanthidium, subsequently Hystrichosphaeridium, thirdly (and now) Baltisphaeridium (an acritarch genus). According to Wilkinson, 1849, "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 ...".
Holotype: Wilkinson, 1849, pl.13, fig.1
Age: Late Cretaceous