Some more recent workers in the field have expressed uncertainty as to the taxonomic placement of this group.

The taxonomic placement of this species has been problematic.

The exact taxonomic placement of this group was initially uncertain and controversial.

Different taxonomic placements may well lead to different correct names.

The taxonomic placement of the Mitrastemon was unsure for a long time.

Those with a question mark preceding the name have an uncertain taxonomic placement.

It is of uncertain taxonomic placement within the order Eurypterida.

The current taxonomic placement is within the order of Oxalidales.

Genera with a question mark preceding them have an uncertain taxonomic placement in the family.

The correct taxonomic placement of this species has been problematic for some years.