A member of the avian lineage of theropod dinosaurs. The extent of the named group can differ between crown-based and broader fossil usages.
A toothed Late Cretaceous bird outside Aves in crown usage, important for comparisons of the avian skull.
A Late Jurassic avian-lineage theropod dinosaur outside the living-bird crown group under standard relationships.
Used here for the crown group of birds: the last common ancestor of living palaeognaths and neognaths and all descendants. Broader historical definitions also occur and should be stated explicitly.
The crown-bird lineage containing Galloanserae and other living birds outside Palaeognathae. Taxonomic membership and possession of a particular mobile palate are different claims.
The crown-bird lineage containing ostriches, emus, kiwis, tinamous and relatives. Its palaeognathous palate is an anatomical specialization, not evidence that its members are ancestors of neognaths.
A corvid, including Corvus corax, used in studies of social information and caching.
A radiation of Galápagos and nearby finches important in studies of ecological divergence, song and hybridization.
The owl called Tyto alba in the cited sibling-negotiation experiments.
