Enaliornis new NT

Restoration of Enaliornis

Hesperornithines is the group of toothed swimming birds of the Cretaceous.

Anatomy and ecology[]

Like modern sea birds, Hesperornithines were built to swim in the water. They had streamlined bodies allowing them to dart through the water and catch fish. Unlike most sea birds, Hesperornithines did not have webbed feet but rather had paddle like fleshy lobes on each toe that would’ve served the same purpose. It is likely that Hesperornithines shared a similar niche to those of modern sea birds, they fed on fish and were likely the prey of marine predators such as sharks and Mosasaurs.


Hesperornithines evolved in the Early Cretaceous Period, about 100 million years ago. The earliest known species had developed wings and may have been capable of flight. As they evolved they lost flight and essentially lost wings altogether, as their wings would’ve been small lobes or may not have even been visible in life. By the end of the Cretaceous they had became relatively large reaching lengths of nearly 2.2 feet. The last Hesperornithines went extinct 66 million years ago in the Cretaceous-Paleogene extinction event.


Despite being close relatives, Hesperornithines were not part of the clade that would evolve into modern birds, instead they branched away before modern birds evolved. It has been proposed that Hesperornithines belong in an order called Hesperornithiformes however this is disagreed upon and not treated as a valid order.

Common Members[]

Common members include Asiahesperornis, Baptornis, Brodavis, Canadaga, Chupkaornis, Coniornis, Enaliornis, Fumicollis, Hesperornis, Judinornis, Parahesperornis, Pasquiaornis, and Potamornis.