(i.e., show all the descendants of a common ancestor). Their basic unit, the clade, is equivalent to the taxon, and their using the clade implies that taxa should reflect evolutionary relationships. Similarly, among those contemporary taxonomists working with the traditional Linnean (binomial) nomenclature, only a few still propose taxa they know to be paraphyletic.

An example of a long-established taxon that is paraphyleticmeaning not also a cladeis the class