BBC: Hesperornis: A large flightless swimming bird from the Late Cretaceous is described.
Carnegie Museum of Natural History News: Gansus: Press release talking about the discovery of fossils of an ancient aquatic bird. Includes photos of the fossils and pictures of what this bird might have looked like.
Ichthyornis: Description of the discovery of a toothed flying sea bird from the Late Cretaceous.
OZ fossils: Nannantius: Talks about a bird discovered in Australia that lived 65 million years ago. Also describes "opposite birds", their characteristics, and their relationship to modern birds.