Hesperornithes is an extinct and highly specialized group of aquatic avialans closely related to the ancestors of modern birds. They inhabited both marine...

definition: "extant birds and all other taxa, such as Ichthyornis and Hesperornithes, that are closer to extant birds than is Archaeopteryx". Later he and...

2001: Potamornis skutchi. This was almost certainly a member of the Hesperornithes, the hefty and toothed flightless diving birds of the Mesozoic seas...

exists for the ecology of B. advenus than for any other member of the Hesperornithes, with the possible exception of Hesperornis regalis, but still much...

mid-Maastrichtian age, about 67 million years ago. It was a member of the Hesperornithes, flightless toothed seabirds of the Cretaceous. Among these, it belonged...

bizarre as Yungavolucris and Avisaurus. Though mostly small, marine Hesperornithes became relatively large and flightless, adapted to life in the open...

archaic clades of birds, such as Enantiornithes, Ichthyornithes, and Hesperornithes, persisted to the latest Maastrichtian but became extinct during the...

of enantiornithe and ornithurine forms. Though mostly small, marine hesperornithes became relatively large and flightless, adapted to life in the open...

Ornithomimosauria, Oviraptorosauria, Deinonychosauria, Enantiornithes, and Hesperornithes. Only the Neornithes, otherwise known as modern birds, survived, and...

penguins, ratites, and terror birds also filled niches left by the hesperornithes and other extinct dinosaurs. Pronounced cooling in the Oligocene resulted...