Ichthyornis

Ichthyornis Temporal range: Late Cretaceous,[1] 95–83.5 Ma PreꞒ Ꞓ O S D C P T J K Pg N
Cast skeleton, Rocky Mountain Dinosaur Resource Center
Scientific classification
Domain:	Eukaryota
Kingdom:	Animalia
Phylum:	Chordata
Clade:	Dinosauria
Clade:	Saurischia
Clade:	Theropoda
Clade:	Avialae
Clade:	Ornithurae
Clade:	†Ichthyornithes
Genus:	†Ichthyornis Marsh, 1873
Species:	†I. dispar
Binomial name
†Ichthyornis dispar (Marsh, 1872)
Synonyms
Angelinornis Kashin 1972 Colonosaurus Marsh, 1872c Plegadornis Wetmore 1962 (preoccupied) Species synonymy Graculavus anceps Marsh, 1872a Ichthyornis anceps (Marsh 1872a) Marsh 1872b Colonosaurus mudgei Marsh, 1872c Graculavus agilis Marsh, 1873b Ichthyornis agilis (Marsh, 1873b) Marsh 1880 Ichthyornis victor Marsh, 1876 Ichthyornis validus Marsh, 1880 Plegadornis antecessor Wetmore, 1962 Angelinornis antecessor (Wetmore, 1962) Kashin 1972 Ichthyornis antecessor (Wetmore, 1962) Olson 1975

Ichthyornis (meaning "fish bird", after its fish-like vertebrae) is an extinct genus of toothy seabird-like ornithuran from the late Cretaceous period of North America. Its fossil remains are known from the chalks of Alberta, Alabama, Kansas (Greenhorn Limestone), New Mexico, Saskatchewan, and Texas, in strata that were laid down in the Western Interior Seaway during the Turonian through Campanian ages, about 95–83.5 million years ago. Ichthyornis is a common component of the Niobrara Formation fauna, and numerous specimens have been found.

Ichthyornis has been historically important in shedding light on bird evolution. It was the first known prehistoric bird relative 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 ornithurans known from more than a few specimens.