The diversity of Psittaciformes in South America and Australasia suggests that the order has a Gondwanan origin, while the center of origins appears to be Australasian.[8] The parrot family's fossil record, however, is sparse and their origin can so far only be inferred.
A single 15 mm fragment from a large lower bill (UCMP 143274), found in Lance Creek Formation deposits of Niobrara County, Wyoming, has been suggested as the first parrot fossil.[9] Of Late Cretaceous age, it is about 70 million years old. But subsequent reviews[10][11] have established that this fossil is almost certainly not from a bird, but from a caenagnathid theropod—a non-avian dinosaur with a birdlike beak.
It is now generally assumed that the Psittaciformes or their common ancestors with a number of related bird orders were present somewhere in the world around the Cretaceous–Tertiary extinction event, some 65 mya (million years ago). If so, they probably had not evolved their morphological autapomorphies yet, but were generalized arboreal birds, roughly similar (though not necessarily closely related) to today's potoos or frogmouths (see also Palaeopsittacus below).
Europe is the origin of the first generally accepted parrot fossils. The first is a wingbone of Mopsitta tanta, uncovered in Denmark and dated to 54 mya (million years ago).[12] The climate at this time was tropical, consistent with the Paleocene-Eocene Thermal Maximum.
Later fossils date from the Eocene, starting around 50 mya. Several fairly complete skeletons of parrot-like birds have been found in England and Germany.[13] Some uncertainty remains, but on the whole it seems more likely that these are not direct ancestors of the modern parrots, but related lineages which evolved in the Northern Hemisphere but have since died out. These are probably not "missing links" between ancestral and modern parrots, but rather psittaciform lineages that evolved parallel to true parrots and cockatoos and had their own peculiar autapomorphies:
- Psittacopes (Early/Middle Eocene of Geiseltal, Germany) – basal?
- Serudaptus – pseudasturid or psittacid?
- Pseudasturidae (Halcyornithidae may be correct name)
- Pseudasturides – formerly Pseudastur
- Quercypsittidae
- Quercypsitta (Late Eocene)
The earliest records of modern parrots date to about 23–20 mya and are also from Europe. Subsequently, the fossil record—again, mainly from Europe—consists of bones clearly recognizable as belonging to parrots of modern type. The Southern Hemisphere does not have nearly as rich a fossil record for the period of interest as the Northern, and contains no known parrot-like remains earlier than the early to middle Miocene, around 20 mya. At this point, however, is found the first unambiguous parrot fossil (as opposed to a parrot-like one), an upper jaw which is indistinguishable from that of modern cockatoos. A few modern genera are tentatively dated to a Miocene origin, but their unequivocal record stretches back only some 5 million years (see genus articles for more). The named fossil genera of parrots are probably all in the Psittacidae or close to its ancestry:
- Archaeopsittacus (Late Oligocene/Early Miocene)
- Xenopsitta (Early Miocene of Czechia)
- Psittacidae gen. et spp. indet. (Bathans Early/Middle Miocene of Otago, New Zealand) - several species
- Bavaripsitta (Middle Miocene of Steinberg, Germany)
- Psittacidae gen. et sp. indet. (Middle Miocene of France) - erroneously placed in Pararallus dispar, includes "Psittacus" lartetianus
Some Paleogene fossils are not unequivocally accepted to be of psittaciforms:
- Palaeopsittacus (Early — Middle Eocene of NW Europe) - caprimulgiform (podargid?) or quercypsittid?
- "Precursor" (Early Eocene) - part of this apparent chimera seems to be of a pseudasturid or psittacid
- Pulchrapollia (Early Eocene) — includes "Primobucco" olsoni - psittaciform (pseudasturid or psittacid)?
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