Ara macao (Linneaus 1758; extant ) is the scarlet macaw. Here it nests with the giant Eocene parrot, Gastornis. Both are among the few birds that separate the orbit from the temporal fenestrae. In parrots digit 4 (mislabeled above) extends posteriorly along with digit 1.

Melopsittacus undulatus (Shaw 1805; extant ) is the extant budgerigar, a tiny parrot. Here the nasal wraps around the ventral naris. The lacrimal forms a send jugal below the orbit and contacts the postorbital and squamosal, as in the extant parrot, Ara, and the giant parrot, Gastornis.

Nestor notabilis (Gould 1856) is the extant kea, 48 cm long and restricted to New Zealan. It is the world's only alpine parrot. Omnivorous, it nests in burrows or root crevices. The kea is known for its intellgence.

Gastornis parisiensis (Hebert 1855, Matthew et al. 1917; Middle Paleocene to Eocene) is one of several species, including G. (formerly Diatryma) gigantea. Derived from a sister to Opisthocomus, the hoatzin, Gastornis nests as a sister to Ara. Likely an herbivore, Gastornis had vestigial forelinmbs, cursorial hind limbs and redeveloped an upper temporal fenestra with an enlarged postfrontal, postorbital and squamosal, as in parrots.

Cope ED 1876. On a gigantic bird from the Eocene of New Mexico. Proceedings of the Academy of Natural Sciences of Philadelphia 28 (2): 10–11.

Gould J 1856. On twon new species of birds (Nestor notabilis and Spatula variegata) from the collection of Walter Mantell, Esq. Proceedings of the Zoological Society of Longon 24:94–95.

Hébert E 1855a. Note sur le tibia du Gastornis pariensis [sic] [Note on the tibia of G. parisiensis]. C. R. Hebd. Acad. Sci. Paris (in French) 40: 579–582.

Hébert E 1855b. Note sur le fémur du Gastornis parisiensis [Note on the femur of G. parisiensis]. C. R. Hebd. Acad. Sci. Paris (in French) 40: 1214–1217.

Linnaeus C 1758. Systema naturæ per regna tria naturæ, secundum classes, ordines, genera, species, cum characteribus, differentiis, synonymis, locis. Tomus I. Editio decima, reformata.

Matthew WD, Granger W and Stein W 1917. The skeleton of Diatryma, a gigantic bird from the Lower Eocene of Wyoming. Buletin of the American Museum of Natural History, 37(11): 307-354.

Owen R 1843. On the remains of Dinornis, an extinct gigantic struthious bird. Proceedings of the Zoological Society of London: 8–10, 144–146.

Prévost C 1855. Annonce de la découverte d'un oiseau fossile de taille gigantesque, trouvé à la partie inférieure de l'argile plastique des terrains parisiens [Announcement of the discovery of a fossil bird of gigantic size, found in the lower Argile Plastique formation of the Paris region]. C. R. Hebd. Acad. Sci. Paris (in French) 40: 554–557.

Shaw 1805. xxx

wiki/Gastornis
wiki/Ara
wiki/Kea
wiki/Budgerigar- Melopsittacus