Paraspecies
A paraspecies is a species, living or fossil, that gave rise to one or more daughter species without itself becoming extinct. Geographically widespread species that have given rise to one or more daughter species as peripheral isolates without themselves becoming extinct are examples of paraspecies.
Paraspecies are expected from evolutionary theory, and are empirical realities in many terrestrial and aquatic taxa.
The evolution of the polar bear from the brown bear is a well-documented example of a living species that gave rise to another living species.
Another example of a living paraspecies is New Zealand's North Island tuatara Sphenodon punctatus, which gave rise to the Brothers Island tuatara Sphenodon guntheri. A third example of a living paraspecies is Empidonax occidentalis, the Cordilleran flycatcher.
