Platycercus, Vigors, 1825

Smith, Brian Tilston, Thom, Gregory & Joseph, Leo, 2024, Revised Evolutionary And Taxonomic Synthesis For Parrots (Order: Psittaciformes) Guided By Phylogenomic Analysis, Bulletin of the American Museum of Natural History 2024 (468), pp. 1-87 : 60

Platycercus

Rosellas ( Platycercus ) are small to midsized parrots that have radiated entirely within Australia including Tasmania. They are among the most easily diagnosable of any parrot genus on plumage by their uniquely mottled upperparts and prominent mono- or bicolored cheek patches. The phylogenomic trees parallel the results from prior multilocus data in supporting two groups sometimes recognized as subgenera ( Shipham et al., 2015). The nominotypical subgenus Platycercus comprises blue-cheeked species Platycercus caledonicus of Tasmania and islands of Bass Strait, and the P. elegans complex of mainland southeastern Australia (the blue-cheeked crimson rosella complex); those sometimes placed in subgenus Violania comprises species having white, bicolored blue and white, or yellow cheeks ( icterotis , eximius , adscitus , and venustus). Both a multilocus ( Shipham et al., 2015) and the phylogenomic tree presented here showed the placement of P. icterotis of southwestern Western Australia as unresolved or poorly supported as sister to the rest of Violania . Our analyses accord with those of Shipham et al. (2015, 2017) who showed that mtDNA of mainland P. eximius has been captured by that of nonsister species P. adscitus , which occurs to its north and with which it has a complex hybrid zone ( Shipham et al., 2019); the mtDNA of P. eximius diemensis of Tasmania is “true” P. eximius mtDNA.

Notably, the P. elegans group has long been a focus of work in speciation and systematics particularly after it was proposed by Cain (1955) as an example of a ring species. Our sampling was not designed to address these issues, but genomic testing of earlier work by Joseph et al. (2008) rejecting the ring species hypothesis is long overdue.