They also define their taxonomic levels as clades and do not apply Linnean hierarchies.

In practice, a number of taxonomic levels have been introduced.

While the rule has been demonstrated in many instances, it does not hold true at all taxonomic levels, or in all clades.

Description is on taxonomic level of genus.

Of the 134 bird species found on Siberut, 19 are endemic at some taxonomic level.

It has been studied at various taxonomic levels, through different time periods and across many geographic regions.

As the taxonomic level decreases, the pattern of taxa abundance approaches a lognormal distribution.

At all taxonomic levels, gastropods are second only to the insects in terms of their diversity.

Ongoing revisions of the higher taxonomic levels are expected in the near future.

There is no unique generally accepted system at the higher taxonomic levels and there are frequent name changes at every level, from species upwards.