The term relict has been used in many ways and has lost its clarity. The author believes it should be used in its common sanse meaning only, to signify a small remaining quantity of something. It therefore cannot be used to designate a new, isolated invasion group, nor to describe a newly evolved geographically isolated taxon. Two main categories of remnants are phylogenetic relicts and geographical relicts. The former are remnants of a previously more widespread and diversified group of species, and the latter are remnants of a formerly more widespread population of a single taxon.