Some Cenozoic avian stuff:
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We describe a nearly complete, threeâdimensionally preserved skull of a new albatross species from the late Pliocene (3.0-3.4 million years ago) Tangahoe Formation of New Zealand. Aldiomedes angustirostris, n. gen. et sp. has only about 90% of the length of the skull of the smallest extant albatross and is the geologically youngest record of a smallâsized albatross known to date. The new species is characterized by a mediolaterally compressed beak, which is not found in any living albatross. The small size and some cranial features of A. angustirostris indicate that, in spite of its comparatively young geological age, the new species was not part of crown group Diomedeidae. We hypothesize that A. angustirostris was more piscivorous than extant albatrosses, which predominantly feed on squid. The reasons for the extinction of smallerâsized albatrosses are elusive but may be related to changes in seabird fauna during the Pliocene epoch, which witnessed the radiation of various nonâprocellariiform seabird groups.
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Lithornithids are volant stem palaeognaths from the PaleoceneâEocene. Except for these taxa and the extant neotropical tinamous, all other known extinct and extant palaeognaths are flightless. Investigation of properties of the lithornithid wing and its implications for inference of flight style informs understood locomotor diversity within Palaeognathae and may have implications for estimation of ancestral traits in the clade. Qualitative comparisons with their closest extant volant relatives, the burstâflying tinamous, previously revealed skeletal differences suggesting lithornithids were capable of sustained flight, but quantitative work on wing morphology have been lacking. Until comparatively recently, specimens of lithornithids preserving wing feather remains have been limited. Here, we reconstruct the wing of an exceptionally preserved specimen of the Early Eocene lithornithid Calciavis grandei and estimate body mass, wing surface area, and wing span. We then estimate flight parameters and compare our estimates with representatives from across Aves in a statistical framework. We predict that flight in C. grandei was likely marked by continuous flapping, and that lithornithids were capable of sustained flight and migratory behavior. Our results are consistent with previous hypotheses that the ancestor of extant Palaeognathae may also have been capable of sustained flight.Â