Santonian birds

Patagopteryx is an extinct monotypic genus of euornithean dinosaurs that lived during the Late Cretaceous, around 80 mya, in what is now the Sierra Barrosa in northwestern Patagonia, Argentina. About the size of a chicken, it is the earliest known unequivocal example of secondary flightlessness: its skeleton shows clear indications that the ancestors of Patagopteryx were flying animals, though other studies find earlier diverging theropods to be secondarily flightless.

Parahesperornis is a genus of prehistoric flightless birds from the Late Cretaceous. Its range in space and time may have been extensive, but its remains are rather few and far between, at least compared with its contemporary relatives in Hesperornis. Remains are known from central North America, namely the former shallows of the Western Interior Seaway in Kansas. Found only in the upper Niobrara Chalk, these are from around the Coniacian-Santonian boundary, 85–82 million years ago (mya). thumb|left|Photograph of scutes and feather impressions of the tarsal region of specimen (KUVP 2287) publ

Neuquenornis volans is a species of enantiornithean birds which lived during the late Cretaceous period in today's Patagonia, Argentina. It is the only known species of the genus Neuquenornis. Its fossils were found in the Santonian Bajo de la Carpa Formation, dating from about 85-83 million years ago. This was a sizeable bird for its time, with a tarsometatarsus 46.8mm long. Informal estimates suggest that it measured nearly 30 cm (12 in) in length excluding the tail.

Apatornis is a genus of ornithuran dinosaurs endemic to North America during the late Cretaceous. It currently contains a single species, Apatornis celer, which lived around the Santonian-Campanian boundary, dated to about 83.5 million years ago. The remains of this species were found in the Smoky Hill Chalk of the Niobrara Formation in Kansas, United States. It is known from a single fossil specimen: a synsacrum, the fused series of vertebrae over the hips.

Bauxitornis is an extinct genus of avisaurid enantiornithean birds which lived in what is now Hungary during the late Cretaceous period (Santonian age). Although first mentioned in a 2008 review of Hungarian Cretaceous bird fossils, it was named in a more comprehensive review by Gareth J. Dyke and Attila Ősi in 2010. The type species is Bauxitornis mindszentyae. The generic name "Bauxitornis" refers to the locality at which it was discovered, a Bauxite mine. The specific name "mindszentyae" honors Andrea Mindszenty, Ősi's advisor.

Fumicollis is a genus of prehistoric flightless birds from the Late Cretaceous (Coniacian-Santonian) Niobrara Chalk of Kansas.