Hypothetical species

Several species have been assumed to exist, but due to a lack of physical evidence they can only be regarded as potential species. Hypothetical species are usually believed to be extinct. They have caused confusion, as they may have been a separate species, a subspecies, an introduced species or a misidentification.[1]

A 1722 illustration by Jean-Baptiste Labat of three parrots on Guadeloupe. There are no remains of these parrots and so accurate taxonomic classification is impossible.