After Brown & Toft, 1999, and Dyke & Cooper, 2000

<==o Psittaciformes Wagler, 1827 (parrots; papukaijalinnut)
   |-- †Psittacopes lepidus Mayr & Daniels, 1998
   `--+--o †Quercypsitta Mourer-Chauviré, 1992 [Quercypsittidae Mourer-Chauviré, 1992]
      |  |-- †Q. sudrei Mourer-Chauviré, 1992
      |  `-- †Q. ivani Mourer-Chauviré, 1992
      `--+-- †Pulchrapollia gracilis Dyke & Cooper, 2000 (beautiful parrot, “graceful; gracile pretty polly”!!)
         `--o “Psittacoidea” [Psittacidae sensu tradionalis] [sensu Dyke & Cooper, 2000] (modern parrots; nykypapukaijat)
            |-- Psittacidae (parrots; papukaijat)
            `--+-- Loriidae (lories and lorikeets; lorit)
               `-- Cacaduidae (cockatoos; kakadut)

Psittaciformes incertae sedis:

Paleopsittacus georgei Harrison, 1982b

Alternative phylogeny of basal Psittaciformes after Mayr, 2002

<==o Psittaciformes
   |?- †Precursor parvus Harrison & Walker, 1977
   |--o †Pseudasturidae Mayr, 1998a
   |  |-- †Pseudastur macrocephalus Mayr, 1998a
   |  |-- †Serudaptus pohli Mayr, 2000b
   |  `--o †Pulchrapollia Dyke & Cooper, 2000
   |     |?- †P. olsoni (Feduccia & Martin, 1976) [†“Primobucco” olsoni Feduccia & Martin, 1976]
   |     `-- †P. gracilis Dyke & Cooper, 2000 [could be jr. synon. to P. olsoni (Mayr, 2002)]
   `--+-- †Psittacopes
      |-- †Quercypsitta
      `--o “Psittacoidea” [Psittacidae sensu tradionalis] [sensu Dyke & Cooper, 2000] (modern parrots; nykypapukaijat)
         |-- Psittacidae (parrots; papukaijat)
         `--+-- Loriidae (lories and lorikeets; lorit)
            `-- Cacaduidae (cockatoos; kakadut)

Reference(s):