Hypothetical species
Several species have been assumed to exist, but due to a lack of physical evidence they can only be regarded as hypothetical or 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. It can also refer to species that are hypothesised to have existed evolutionarily.
List of hypothetical species
Birds
- Albin's macaw
- Arkansaw siskin, Fringilla spaltria
- Barraband's mystery black-breasted twelve-wired bird-of-paradise
- Bird of Washington, Haliaetus washingtoni
- Blue-browed fig parrot
- Blue Mountain warbler, Sylvia montana
- Blue-thighed lory, Lorius tibialis
- Dominican green-and-yellow macaw, Ara atwoodi
- Carbonated warbler, Sylvia carbonata
- Cuvier's kinglet, Regulus cuvieri
- Geoffroyus aureus
- Guadeloupe amazon, Amazona violacea
- Guadeloupe parakeet, Psittacara labati
- Hypothetical relatives of the Rodrigues parrot
- Jago fowl, Gallus giganteus
- Jamaican red macaw, Ara gossei
- Leguat's giant, Leguatia gigantea
- Lesser Antillean macaw, Ara guadeloupensis
- Madeira finch, Goniaphea leucocephala
- Martinique amazon, Amazona martinicana
- Martinique macaw, Ara martinicus
- Meidum geese
- Painted vulture, Sarcoramphus sacra/''Sarcoramphus papa ssp.
- Raiatea starling, Aplonis? ulietensis
- Red-headed macaw, Ara erythrocephala
- Roper River scrub robin, Drymodes superciliaris colcloughi
- Réunion swamphen, Porphyrio caerulescens
- Small-headed flycatcher, Muscicapa minuta
- Sushkin's goose, Anser neglectus
- Tahiti crake, Zapornia nigra
- Tanna ground dove, Pampusana ferruginea
- Townsends' dickcissel, Spiza townsendi
- Townsend's finch, Emberiza townsendi
- Unicolored lory, Eos unicolor''
- Unidentified Jamaican parrot
- Zhenniao
Non-avian dinosaurs
- ''Proavis''
Mammals
- Andean wolf, Dasycyon hagenbecki
- Chilihueque, Lama araucana
- Chinese elephant, Elephas maximus rubridens
- Javan elephant, Elephas maximus sondaicus
- Giraffa sahara
- Kallana
- Long-necked seal, Phoca mutica
- Shrewdinger
- Sonnerat's shrew, Diplomesodon sonnerati
- Steller's sea ape, Simia marina
- Sumxu
- Unidentified extinct canid populations
- Waitoreke
- Zebro
Fish
- Abyssal rainbow gar
- Five-lined constellation fish, Bathysidus pentagrammus
- Giant dragonfish, Bathysphaera intacta
- Pallid sailfin, Bathyembryx istiophasma
- Three-starred anglerfish, ''Bathyceratias trilynchnus''
Arthropods
- Acarus crossi
- Battus polydamas antiquus
- Euploea rogeri
- Guam glider, Neptis guamensis
- ''Papilio antizox''
Other invertebrates
Plants
- Laysan fan palm, Pritchardia? sp.
- Silphium