Monotypic Taxon

In biology, a monotypic taxon is a taxonomic group that contains only one immediately subordinate extant taxon, most often used at the rank of genus or family: a monotypic genus has only one living species, and a monotypic family only one living genus. For a genus specifically, the terms unispecific and monospecific are sometimes used instead, and in botanical nomenclature a genus is described as monotypic when it and its single extant species are described at the same time. The term is also applied the other way around to a species that is the sole extant member of its genus. The cuckoo roller, the only living member of its own genus, family, and order all at once, is a commonly cited example. This description is adapted from Wikipedia contributors under CC BY-SA 4.0; changes were made. https://creativecommons.org/licenses/by-sa/4.0/