Hesperornis was a flightless aquatic bird that lived during the Late Cretaceous period on the Northern Hemisphere. Some species were as tall as a human being, reaching 1.8 meters high! Its wings were very small and weren’t used for swimming. Hesperornis’ feet were strong and muscled and its toes were lobed instead of webbed. By using these, it was able to dive for prey in big lakes and oceans, like cormorants do nowadays. Its toothed-beak gave him an advantage for hunting prey underwater, because it could grab and hold on to them while swimming back to the surface.
Hesperornis regalis is one of nine species within the genus and lived in what is now North America. It was discovered by Othniel Charles Marsh in the late 19th century and sparked the bone wars, also called the Great Dinosaur Rush. Some Hesperornis fossils were accidentally sent to Marsh’ rival and was accused of theft.
Zinoviev, A. V. (2011). Notes on the hindlimb myology and syndesmology of the Mesozoic toothed bird Hesperornis regalis (Aves: Hesperornithiformes). Journal of Systematic Palaeontology, 9(1), 65-84.