Expecies
Expecies is a term used in biology and philosophy to describe populations or organisms that do not fit neatly within the conventional species concept. It is not an officially recognized taxonomic rank, but a descriptive label employed in discussions about the boundaries and limitations of species classification. The word combines ex- meaning outside or beyond with species.
Expecies can apply in cases where criteria such as reproductive isolation are ambiguous or incomplete, yet
There is no universal set of criteria for designating an expecies. Proposals typically emphasize genetic divergence,
Expecies sits alongside discussions of cryptic species, paleospecies, and hybrid species, highlighting the challenges of applying
Species concept, cryptic species, paleospecies, polyploidy, hybridization.