Ichthyornis (meaning "fish bird", after its fish-like vertebrae) was a genus of toothed seabirds from the Late Cretaceous Period of North America. Its fossil remains are known from the chalks of Alberta, Alabama, Kansas, New Mexico, Saskatchewan, and Texas, in strata that were laid down in the Western Interior Seaway during the Turonian-Campanian ages, about 95-85 mya). Ichthyornis is a common component of the Niobrara Formation fauna, and numerous specimens of both adult and immature individuals have been found. These particular Ichthyornis are showcased in the Walt Disney feature film Dinosaur.
Ichthyornis has been historically important in shedding light on bird evolution. It was the first discovered prehistoric bird preserved with teeth, and Charles Darwin noted its significance during the early years of the theory of evolution. Ichthyornis remains important today as it is one of the few Mesozoic era birds known from more than a few specimens.
Ichthyornis are common birds that live in the world of Dinosaur. They apparently feed on fish because they are seen near lakes and on the island where the lemurs live. A flock of them were at the lake in the nesting grounds at the beginning of the film when a babyParasaurolophus leapt through it, causing several of them to fly up. Several more were near the cliffs of Lemur Island when two of them mobbed a Pteranodon as it was flying back to its nest with Aladar's egg, causing it to drop the egg. More of them flew away from the island as the meteor hit the ocean.