Although this may mean some of the these species should be lumped, they believe the confused situation is due to ancient hybridization. (2014) all identified the parrots as the sister group to the passeriformes. Stem parrot fossils have been found from the early Eocene of India (Vastanavis), Europe (Halcyornithidae, Psittacopes), and North America (Tynskya), see Mayr (2009), and Mayr et al., (2013).Further analysis is required to sort out the Hierofalco complex. The overall structure of the Psittaciformes follows Schirtzinger et al. The extant order is summed up in the following tree diagram.Of the two main clades, Psittaculidae is slightly larger, so we put it last in the linear order. (2012) also included Psilopsiagon in their analysis, putting it here in the Amoropsittacini.The Neotropical parrots, Arinae, fall into 5 subclades: Amoropsittacini, Brotogerini, the clade of large short-tailed parrots, Androglossini, Forpus parrotlets (Forpini), and a narrowly circumscribed conure/macaw clade Arini. The Brotogerini appear to be affiliated with the Androglossini, and the Forpini with the core Arini.The parrots from Pionopsitta to Pyrilia were studied by Ribas et al. The ordering of the Pionus parrots reflects the results of Ribas et al. The results also support a possible split of White-capped Parrot, Pionus seniloides. (2012) found a substantial amount of genetic structure in the Mealy Amazon, Amazona farinosa.The Hapalopsittaca order is based on Quintero et al. The Central American populations to west Panama (guatemalae and virenticeps) formed a separate clade from those in the Darien and South America (inornata and farinosa/chapmani), with 3.5-5.4% genetic distance in cytochrome-b.Passerimorphae also appear as a clade (under the name Eufalconimorphae) in Suh et al. They use the completely different approach of retroposon insertions to investigate avian phylogeny. Although there are currently only two species of Seriemas, they are a remnant of a much larger group, the Cariamae.They also note the similarities in the vocal apparatus and the fact that both parrots and many passeriformes learn their song. (2014) found it strongly supported in everything but the exon data (which don't support very much of anything). (2014) found them sister to the remaining three orders, while Ericson et al. Like the Cariamidae, the Cariamae have traditionally been placed in the Gruiformes. The oldest fossils are from Phorusrhacidae, dating back to the late Paleocene in Brazil, which matches well with the divergence estimate for the Cariamidae by Jarvis et al. The Phorusrhacidae are the well-known “terror birds” of ancient South America. They found that crown-group Falconidae date to the Oligocene.
That's Bonaparte himself the following year, when he gave priority to Strigopidae by listing Nestorinae as a subfamily (1850, Vol. Interesting, the current Zanda diversity appeared very recently, whereas the split between the two Calyptorhynchus is of much longer standing. The appear to be sister groups, as do the Psittrichasinae and Psittaculinae, leaving us with two major clades: Psittacidae (Psittacinae and Arinae) and Psittaculidae (Psittrichasinae and Psittaculinae). The earlier dating suppose that the New Zealand Parrots date from the separation of New Zealand from Gondwana, over 80 million years ago.
Such differences usually indicate separate species, and I treat them as such: the Northern Mealy Amazon, Amazona guatemalae, and Southern Mealy Amazon, Amazona farinosa.
Some uncertainty remains here as they did not look in detail at the situation within Panama where the two clades are in contact.
I can't find an alternate name for the Amazonian ochrocephala, so I've labelled them as ochrocephala (Amazon) and ochrocephala (Orinoco).
The literature refers to a Central (meaning Middle) American clade, Northern South American (NSA) clade and two South American clades (SA1 and SA2).