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Relationships and species limits among the colourful Australian parrots known as rosellas ( Platycercus ) are contentious because of poorly understood patterns of parapatry, sympatry and hybridization as well as complex patterns of geographical replacement of phenotypic forms. Two subgenera are, however, conventionally recognised: Platycercus comprises the blue-cheeked crimson rosella complex (Crimson Rosella P. elegans and Green Rosella P. caledonicus ), and Violania contains the remaining four currently recognised species (Pale-headed Rosella P. adscitus , Eastern Rosella P. eximius , Northern Rosella P. venustus , and Western Rosella P. icterotis ). We used phylogenetic analysis of ten loci (one mitochondrial, eight autosomal and one z-linked) and several individuals per nominal species primarily to examine relationships within the subgenera, especially the relationships and species limits within Violania . Of these, P. adscitus and P. eximius have long been considered sister species or conspecific due to a morphology-based hybrid zone and an early phylogenetic analysis of mitochondrial DNA restriction fragment length polymorphisms. The multilocus phylogenetic analysis presented here supports an alternative hypothesis aligning P. adscitus and P. venustus as sister species. Using divergence rates published in other avian studies, we estimated the divergence between P. venustus and P. adscitus at 0.0148–0.6124 MYA and that between the P. adscitus / P. venustus ancestor and P. eximius earlier at 0.1617–1.0816 MYA, both within the Pleistocene. Discordant topologies among gene and species trees are discussed and proposed to be the result of historical gene flow and/or incomplete lineage sorting (ILS). In particular, we suggest that discordance between mitochondrial and nuclear data may be the result of asymmetrical mitochondrial introgression from P. adscitus into P. eximius . The biogeographical implications of our findings are discussed relative to similarly distributed groups of birds. [ABSTRACT FROM AUTHOR]

Abstract: The platycercine parrots of Australia, usually recognized as the Platycercinae or Platycercini, are the broad-tailed parrots and their allies typified by the rosellas Platycercus spp. Debate concerning their circumscription has most recently centerd on the position of four genera, Neophema, Neopsephotus, Pezoporus and Psittacella, the last two having never been adequately included in sequence-based analyses. We use broad taxon sampling, mitochondrial and nuclear DNA sequence data from seven independent loci (two linked mitochondrial loci and six nuclear loci), and both gene tree and species tree approaches to reconstruct phylogenies and so determine the systematic placement all four genera. Analyses of two data sets, one of 48 taxa and five loci and one of 27 taxa and the same five plus three additional loci produced broadly congruent and consistently well-resolved phylogenies. We reject placement of any of these four genera within core platycercines. Pezoporus is closely allied to Neophema and Neopsephotus. These three genera are the likely sister group to core platycercines and we advocate their recognition as a subfamily. Psittacella is the sole extant representative of a lineage that branched very early in the history of Australo-Papuan parrot fauna and is not closely related to any of the mostly south-east Asian and Indonesian psittaculine taxa with which it is more often linked. We present a revised view of the extraordinary phylogenetic, phenotypic and ecological diversity that is the adaptive radiation of Australo-Papuan parrots. Finally, our analyses highlight the likely paraphyly of Mayr’s (2008) Loricoloriinae. [Copyright &y& Elsevier]