Internal nodes are generally called hypothetical taxonomic units, as they cannot be directly observed.

In zoology, polytypic refers to a taxonomic unit with more than one subgroup at the next lower level.

Euthecosomata is a taxonomic unit used to classify sea snails.

Attempts to subdivide this large taxonomic unit into separate genera have been made.

Here too, for the first time, the species, rather than the genus, becomes the fundamental taxonomic unit.

For mammals, the taxonomic unit below the species level is usually the subspecies.

Scimitar-toothed cats do not form a taxonomic unit, which means they are not necessarily related to each other.

In formal usage, the name of the taxon shall precede the term for the taxonomic unit.

Depending on the context, a soil series may be defined as either a taxonomic unit or a mapping unit.

A taxonomic unit is a category belonging to a specific level of a classification system.