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Presbyornithids were the dominant birds in Palaeogene lacustrine assemblages, especially in the Northern Hemisphere, but are thought to have disappeared worldwide by the mid-Eocene. Now classified within Anseriformes (screamers, ducks, swans and geese), their relationships have long been obscured by their strange wader-like skeletal morphology. Reassessment of the late Oligocene South Australian material attributed to Wilaru tedfordi, long considered to be of a stone-curlew (Burhinidae, Charadriiformes), reveals that this taxon represents the first record of a presbyornithid in Australia. We also describe the larger Wilaru prideauxi sp. nov. from the early Miocene of South Australia, showing that presbyornithids survived in Australia at least until ca 22 Ma. Unlike on other continents, where presbyornithids were replaced by aquatic crown-group anatids (ducks, swans and geese), species of Wilaru lived alongside these waterfowl in Australia. The morphology of the tarsometatarsus of these species indicates that, contrary to other presbyornithids, they were predominantly terrestrial birds, which probably contributed to their long-term survival in Australia. The morphological similarity between species of Wilaru and the Eocene South American presbyornithid Telmabates antiquus supports our hypothesis of a Gondwanan radiation during the evolutionary history of the Presbyornithidae. Teviornis gobiensis from the Late Cretaceous of Mongolia is here also reassessed and confirmed as a presbyornithid. These findings underscore the temporal continuance of Australia’s vertebrates and provide a new context in which the phylogeny and evolutionary history of presbyornithids can be examined.

Recent mousebirds are the smallest of the living neognathous bird orders -just two genera comprising six species. Understanding the evolutionary dynamics of this avian lineage is important because these birds occupy a critical position within Neoaves and can be used as a model for patterns of morphological diversification in other taxa. We present a review of all known fossil mousebirds (Aves: Coliiformes), which formed a diverse assemblage in the Paleogene (65-23.8 ma). We also present a new phylogenetic analysis including the living and fossil representatives of the order, on the basis of a larger character ⁄ taxon matrix. This analysis suggests that the Lower Eocene Eocolius is the most basal member of clade Coliiformes, while the Lower-Middle Eocene Sandcoleidae form a basal clade with respect to all other known coliiforms. We show that the Eocene taxon Chascacocolius is the sister group of the crown Coliidae, and that the Middle Eocene taxon Selmes is basal to a clade comprising Chascacocolius and Coliidae. On the basis of this phylogenetic analysis, we propose a new classification for the order Coliiformes including two new families, Chascacocoliidae and Selmeidae. For all families (clades) of mousebirds we provide descriptive osteological diagnoses and discuss a number of functional considerations related to the evolution of their hindlimbs; these considerations can be extended across all extant and fossil perching birds because we show that the hindlimb morphology of Coliiformes is strongly related to their lifestyle, as reflected in their evolutionary history.

Two new fossil psittaciform birds from the Lower Eocene 'Mo Clay' (Fur Formation) of Denmark (c. 54 Ma) are described. An unnamed specimen is assigned to the extinct avian family of stem-group parrots, Pseudasturidae (genus and species incertae sedis), while a second (Mopsitta tanta gen. et sp. nov.) is the largest fossil parrot yet known. Both specimens are the first fossil records of these birds from Denmark. Although the phylogenetic position of Mopsitta is unclear (it is classified as family incertae sedis), this form is phylogenetically closer to Recent Pstittacidae than to other known Palaeogene psittaciforms and may, therefore, represent the oldest known crowngroup parrot.

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