Pteranodon is a genus of pterosaur that included some of the largest known flying reptiles, with wingspans over 7 meters. They lived during the late Cretaceous geological period of North America in present-day Kansas, Alabama, Nebraska, Wyoming, and South Dakota. More fossil specimens of Pteranodon have been found than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with nearly complete skulls and articulated skeletons. It was an important part of the animal community in the Western Interior Seaway.
Othniel Charles Marsh was an American professor of Paleontology in Yale College and President of the National Academy of Sciences. He was one of the preeminent scientists in the field of paleontology. Among his legacies are the discovery or description of dozens of new species and theories on the origins of birds.
Hesperornithes is an extinct and highly specialized group of aquatic avialans closely related to the ancestors of modern birds. They inhabited both marine and freshwater habitats in the Northern Hemisphere, and include genera such as Hesperornis, Parahesperornis, Baptornis, Enaliornis, and Potamornis, all strong-swimming, predatory divers. Many of the species most specialized for swimming were completely flightless. The largest known hesperornithean, Canadaga arctica, may have reached a maximum adult length of over 1.5 metres (4.9 ft).
Ichthyornis is an extinct genus of toothed seabird-like ornithuran 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 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.
Hesperornis is a genus of cormorant-like bird that spanned the first half of the Campanian age of the Late Cretaceous period. One of the lesser-known discoveries of the paleontologist O. C. Marsh in the late 19th century Bone Wars, it was an early find in the history of avian paleontology. Locations for Hesperornis fossils include the Late Cretaceous marine limestones from Kansas and the marine shales from Canada. Nine species are recognised, eight of which have been recovered from rocks in North America and one from Russia.
Coelurus is a genus of coelurosaurian dinosaur from the Late Jurassic period. The name means "hollow tail", referring to its hollow tail vertebrae. Although its name is linked to one of the main divisions of theropods (Coelurosauria), it has historically been poorly understood, and sometimes confused with its better-known contemporary Ornitholestes. Like many dinosaurs studied in the early years of paleontology, it has had a confusing taxonomic history, with several species being named and later transferred to other genera or abandoned. Only one species is currently recognized as valid: the type species, C. fragilis, described by Othniel Charles Marsh in 1879. It is known from one partial skeleton found in the Morrison Formation of Wyoming, United States. It was a small bipedal carnivore with elongate legs.
Ichthyornithes is an extinct group of toothed avialans very closely related to the common ancestor of all modern birds. They are known from fossil remains found throughout the late Cretaceous period of North America, though only one species, Ichthyornis dispar, is represented by complete enough fossils to have been named. Ichthyornitheans became extinct at the Cretaceous–Paleogene boundary, along with enantiornitheans, all other non-avian dinosaurs, and many other animal and plant groups.
Nyctosaurus is a genus of nyctosaurid pterosaur from the Late Cretaceous period of what is now the Niobrara Formation of the mid-western United States, which, during the time Nyctosaurus was alive, was covered in an extensive shallow sea. Some remains belonging to a possible Nyctosaurus species called N.lamegoi have been found in Brazil, making Nyctosaurus more diverse. The genus Nyctosaurus has had numerous species referred to it, though how many of these may actually be valid requires further study. At least one species possessed an extraordinarily large antler-like cranial crest.
Polarornis is a genus of prehistoric bird, possibly an anserimorph. It contains a single species Polarornis gregorii, known from incomplete remains of one individual found on Seymour Island, Antarctica, in rocks which are dated to the Late Cretaceous.
Halisaurus is an extinct genus of marine reptile belonging to the mosasaur family. The holotype, consisting of an angular and a basicranium fragment discovered near Hornerstown, New Jersey, already revealed a relatively unique combination of features and prompted a new genus to be described. It was named by Othniel Charles Marsh in 1869 and means "ocean lizard". It was renamed by Marsh to Baptosaurus in 1870, since he believed the name to already be preoccupied by the fish Halosaurus. According to modern rules, a difference of a letter is enough and the substitute name is unneeded, making "Baptosaurus" a junior synonym.
Benjamin Franklin Mudge was an American lawyer, geologist and teacher. Briefly the mayor of Lynn, Massachusetts, he later moved to Kansas where he was appointed the first State Geologist. He led the first geological survey of the state in 1864, and published the first book on the geology of Kansas. He lectured extensively, and was department chair at the Kansas State Agricultural College.
Apatornis is a genus of prehistoric birds 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.
Apsaravis is a Mesozoic bird genus from the Late Cretaceous. The single known species, Apsaravis ukhaana, lived about 78 million years ago, in the Campanian age of the Cretaceous period. Its fossilized remains were found in the Camel's Humps sublocality of the Djadokhta Formation, at Ukhaa Tolgod in the Gobi Desert of Mongolia. They were collected in the 1998 field season by the Mongolian Academy of Sciences/American Museum of Natural History Paleontological Expeditions. It was described by Norell and Clarke (2001).
Limenavis is a prehistoric bird genus from the Late Cretaceous. It lived about 70 million years ago, around the Campanian-Maastrichtian boundary. Known from several broken bones, the remains of the only known species Limenavis patagonica were found in rocks of the "lower member" of the Allen Formation at Salitral Moreno, 20 km south of General Roca, Río Negro (Argentina). It is the closest relative, in the fossil record, of the modern birds.
Graculavus is a prehistoric bird genus that was described in the 19th century by American paleontologist O. C. Marsh. Its remains were found in the Late Cretaceous Austin Chalk of Texas, USA, and Lance Formation, and the controversial Hornerstown Formation which straddles the Cretaceous–Paleocene boundary, possibly dating to the Danian stage. These birds lived on the shores of the northwestern Atlantic and the Western Interior Seaway some 68 to 62 million years ago.
Zhongornis is a genus of primitive avialan that lived during the Early Cretaceous. It was found in rocks of the Yixian Formation in Lingyuan City (China), and described by Gao et al. in 2008.
Chaoyangia is an extinct genus of euornithean birds, containing the single species Chaoyangia beishanensis. This species is known from a single fossil specimen consisting of a partial skeleton including vertebra, ribs, hips, and upper legs. The specimen was discovered in the Jiufotang Formation near the city of Chaoyang in Liaoning province, China. This rock formation has been dated to the Aptian age of the Early Cretaceous period, 120 million years ago.
Pangalliformes is the scientific name of a provisional clade of birds within the group Galloanserae. It is defined as all birds more closely related to chickens than to ducks, and includes all modern chickens, turkeys, pheasants, and megapodes, as well as extinct species that do not fall within the crown group Galliformes.
Julia Allison Clarke is an American paleontologist who is particularly interested in bird evolution and the dinosaurs most closely related to living birds. She works at the University of Texas where she is the John A. Wilson Professor in Vertebrate Paleontology.
Austinornis is a genus of prehistoric birds related to Galliformes. It is known from a fossil of the Late Cretaceous of Texas.
