Instruct: Given a question, retrieve relevant documents that answer the question.
Query: Where was the first Pteranodon fossil found?
Pteranodon was the first pterosaur found outside of Europe. Its fossils first were found by Othniel Charles Marsh in 1870, in the Late Cretaceous Smoky Hill Chalk deposits of western Kansas. These chalk beds were deposited at the bottom of what was once the Western Interior Seaway, a large shallow sea over what now is the midsection of the North American continent. These first specimens, YPM 1160 and YPM 1161, consisted of partial wing bones, as well as a tooth from the prehistoric fish Xiphactinus, which Marsh mistakenly believed to belong to this new pterosaur (all known pterosaurs up to that point had teeth). In 1871, Marsh named the find "Pterodactylus oweni", assigning it to the well-known (but much smaller) European genus Pterodactylus. Marsh also collected more wing bones of the large pterosaur in 1871. Realizing that the name he had chosen had already been used for Harry Seeley's European pterosaur species Pterodactylus oweni in 1864, Marsh re-named his giant North American pterosaur Pterodactylus occidentalis, meaning "Western wing finger," in his 1872 description of the new specimen. He also named two additional species, based on size differences: Pterodactylus ingens (the largest specimen so far), and Pterodactylus velox (the smallest).[6]
The fact that females appear to have outnumbered males two to one suggests that, as with modern animals with size-related sexual dimorphism, such as sea lions and other pinnipeds, Pteranodon might have been polygynous, with a few males competing for association with groups consisting of large numbers of females. Similar to modern pinnipeds, Pteranodon may have competed to establish territory on rocky, offshore rookeries, with the largest, and largest-crested, males gaining the most territory and having more success mating with females. The crests of male Pteranodon would not have been used in competition, but rather as "visual dominance-rank symbols", with display rituals taking the place of physical competition with other males. If this hypothesis is correct, it also is likely that male Pteranodon played little to no part in rearing the young; such a behavior is not found in the males of modern polygynous animals who father many offspring at the same time.[7]
Pteranodon (/tɪˈrænədɒn/; from Greek πτερόν ( pteron, "wing") and ἀνόδων (anodon, "toothless") is a genus of pterosaur that included some of the largest known flying reptiles, with wingspans over 8 meters (26 feet). 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.[1]
All known "Nyctosaurus" fossils come from the Smoky Hill Chalk of Kansas, part of the Niobrara Formation. Specifically, they are found only within a narrow zone characterised by the abundance of ammonite fossils belonging to the species "Spinaptychus sternbergi". These limestone deposits were laid down during a marine regression of the Western Interior Seaway that lasted between 85 and 84.5 million years ago. Therefore, "Nyctosaurus" was a relatively short-lived species, unlike its relative "Pteranodon", which is found throughout almost all of the Niobrara layers into the overlying Pierre Shale Formation, and existed between 88 and 80.5 million years ago.
Fragmentary fossils assigned to Pteranodon have also been discovered in Skåne, Sweden.[23]
Some very fragmentary fossils belonging to pteranodontian pterosaurs, and possibly Pteranodon itself, have also been found on the Gulf Coast and East Coast of the United States. For example, some bone fragments from the Mooreville Formation of Alabama and the Merchantville Formation of Delaware may have come from Pteranodon, though they are too incomplete to make a definite identification.[6] Some remains from Japan have also been tentatively attributed to Pteranodon, but their distance from its known Western Interior Seaway habitat makes this identification unlikely.[6]
The first "Hesperornis" specimen was discovered in 1871 by Othniel Charles Marsh. Marsh was undertaking his second western expedition, accompanied by ten students. The team headed to Kansas where Marsh had dug before. Aside from finding more bones belonging to the flying reptile "Pteranodon", Marsh discovered the skeleton of a "large fossil bird, at least five feet in height". The specimen was large, wingless, and had strong legs—Marsh considered it a diving species. Unfortunately, the specimen lacked a head. Marsh named the find "Hesperornis regalis", or "regal western bird".
Specimens assigned to Pteranodon have been found in both the Smoky Hill Chalk deposits of the Niobrara Formation, and the slightly younger Sharon Springs deposits of the Pierre Shale Formation. When Pteranodon was alive, this area was covered by a large inland sea, known as the Western Interior Seaway. Famous for fossils collected since 1870, these formations extend from as far south as Kansas in the United States to Manitoba in Canada. However, Pteranodon specimens (or any pterosaur specimens) have only been found in the southern half of the formation, in Kansas, Wyoming, and South Dakota. Despite the fact that numerous fossils have been found in the contemporary parts of the formation in Canada, no pterosaur specimens have ever been found there. This strongly suggests that the natural geographic range of Pteranodon covered only the southern part of the Niobrara, and that its habitat did not extend farther north than South Dakota.[6]
It is likely that, as in other polygynous animals (in which males compete for association with harems of females), Pteranodon lived primarily on offshore rookeries, where they could nest away from land-based predators and feed far from shore; most Pteranodon fossils are found in locations which at the time, were hundreds of kilometres from the coastline.[7]
"Geosternbergia" was among the largest pterosaurs, with the wingspan of most adults ranging between . No complete skulls of adult males have been found, but a nearly complete lower jaw has been estimated at long. While most specimens are found crushed, enough fossils exist to put together a detailed description of the animal. "Geosternbergia sternbergi" was very similar to the more well-known pterosaur species "Pteranodon longiceps" and is often considered simply an earlier species of "Pteranodon" itself. It is different from "Pteranodon" mainly due to its earlier time period and broader, more upright crest.
This timeline of pterosaur research is a chronologically ordered list of important fossil discoveries, controversies of interpretation, and taxonomic revisions of pterosaurs, the famed flying reptiles of the Mesozoic era. Although pterosaurs went extinct millions of years before humans evolved, humans have coexisted with pterosaur fossils for millennia. Before the development of paleontology as a formal science, these remains would have been interpreted through a mythological lens. Myths about thunderbirds told by the Native Americans of the modern western United States may have been influenced by observations of "Pteranodon" fossils. These thunderbirds were said to have warred with water monsters, which agrees well with the co-occurrence of "Pteranodon" and the ancient marine reptiles of the seaway over which it flew.
The fossils of the Niobrara chalk may have been influential on these stories. The pterosaur "Pteranodon" and marine reptiles like mosasaurs are preserved in Niobrara Chalk deposits and associated remains may have been interpreted as evidence for antagonism between immense flying animals and serpentine aquatic reptiles. Fossils of the large toothed diving bird "Hesperornis" are also found in the Niobrara chalk, sometimes preserves inside specimens of large predatory marine reptiles. Observations of similar fossils in the past may have been seen as further evidence for thunderbird-water monster conflict.
The Western Interior Seaway was home to early birds also, including the flightless "Hesperornis" which had stout legs for swimming through water and tiny wings used for marine steering rather than flight; and the tern-like "Ichthyornis", an early avian with a toothy beak. "Icthyornis" shared the sky with large pterosaurs such as "Nyctosaurus" and "Pteranodon". "Pteranodon" fossils are very common and it was probably a major component of the surface ecosystem, though it was found in only the southern reaches of the Seaway.
"Tethydraco" was placed in the Pteranodontidae. A cladistic analysis recovered it as the sister species of a clade consisting of "Pteranodon" and "Geosternbergia" (= "Pteranodon sternbergi"). It would then be the youngest known pteranodontid. Its existence was seen as proof that pterosaur diversity in the Maastrichtian was higher than previously assumed. Pterosaur decline was an illusion caused by the Signor–Lipps effect, groups seeming to disappear earlier than a mass extinction because their youngest fossils by chance have been found at somewhat older layers than the extinction event.
With these hypotheses ruled out, the best-supported hypothesis for crest function seems to be as a sexual display. This is consistent with the size variation seen in fossil specimens, where females and juveniles have small crests and males large, elaborate, variable crests.[7]
The ecosystem preserved in this zone was unique in its abundance of vertebrate life. "Nyctosaurus" shared the sky with the bird "Ichthyornis" and with "Pteranodon longiceps", though the second Niobrara "Pteranodon" species, "P. sternbergi", had disappeared from the fossil record by this point. In the waters of the Western Interior Seaway below swam mosasaurs ("Clidastes", "Ectenosaurus" and "Tylosaurus"), the flightless diving bird "Parahesperornis", and a wide variety of fish, including swordfish-like "Protosphyraena", the predatory "Xiphactinus" and the shark "Cretolamna".
Fossils from terrestrial dinosaurs also have been found in the Niobrara Chalk, suggesting that animals who died on shore must have been washed out to sea (one specimen of a hadrosaur appears to have been scavenged by a shark).[18]
Pteranodon species are extremely well represented in the fossil record, allowing for detailed descriptions of their anatomy and analysis of their life history. Over 1,000 specimens have been identified, though less than half are complete enough to give researchers good anatomical information. Still, this is more fossil material than is known for any other pterosaur, and it includes both male and female specimens of various age groups and possibly species.[2]
While the first Pteranodon wing bones were collected by Marsh and Cope in the early 1870s, the first Pteranodon skull was found on May 2, 1876, along the Smoky Hill River in Wallace County (now Logan County), Kansas, USA, by Samuel Wendell Williston, a fossil collector working for Marsh.[1] A second, smaller skull soon was discovered as well. These skulls showed that the North American pterosaurs were different from any European species, in that they lacked teeth and had bony crests on their skulls. Marsh recognized this major difference, describing the specimens as "distinguished from all previously known genera of the order Pterosauria by the entire absence of teeth." Marsh recognized that this characteristic warranted a new genus, and he coined the name Pteranodon ("wing without tooth") in 1876. Marsh reclassified all the previously named North American species from Pterodactylus to Pteranodon. He considered the smaller skull to belong to Pteranodon occidentalis, based on its size. Marsh classified the larger skull, YPM 1117, in the new species Pteranodon longiceps, which he thought to be a medium-sized species in between the small P. occidentalis and the large P. ingens.[20][6] Marsh also named several additional species: Pteranodon comptus and Pteranodon nanus were named for fragmentary skeletons of small individuals, while Pteranodon gracilis was based on a wing bone that he mistook for a pelvic bone. He soon realized his mistake, and re-classified that specimen again into a separate genus, which he named Nyctosaurus. P, nanus was also later recognized as a Nyctosaurus specimen.[21][6]
Because fossils identifiable as P. sternbergi are found exclusively in the lower layers of the Niobrara Formation, and P. longiceps fossils exclusively in the upper layers, a fossil lacking the skull can be identified based on its position in the geologic column (though for many early fossil finds, precise data about its location was not recorded, rendering many fossils unidentifiable).[5]
Pteranodon fossils are known primarily from the Niobrara Formation of the central United States. Broadly defined, Pteranodon existed for more than four million years, during the late Coniacian to early Campanian stages of the Cretaceous period.[6] The genus is present in most layers of the Niobrara Formation except for the upper two; in 2003, Kenneth Carpenter surveyed the distribution and dating of fossils in this formation, demonstrating that Pteranodon sternbergi existed there from 88 to 85 million years ago, while P. longiceps existed between 86 and 84.5 million years ago. A possible third species, which Kellner named Geosternbergia maysei in 2010, is known from the Sharon Springs member of the Pierre Shale Formation in Kansas, Wyoming, and South Dakota, dating to between 81.5 and 80.5 million years ago.[16]
The first "G. sternbergi" fossil was collected by George F. Sternberg in 1952 and described by John Christian Harksen in 1966, from the lower portion of the Niobrara Formation. It was older than "Pteranodon longiceps" and is considered by Bennett to be the direct ancestor of that species.
Paleontology in Kansas refers to paleontological research occurring within or conducted by people from the U.S. state of Kansas. Kansas has been the source of some of the most spectacular fossil discoveries in US history. The fossil record of Kansas spans from the Cambrian to the Pleistocene. From the Cambrian to the Devonian, Kansas was covered by a shallow sea. During the ensuing Carboniferous the local sea level began to rise and fall. When sea levels were low the state was home to richly vegetated deltaic swamps where early amphibians and reptiles lived. Seas expanded across most of the state again during the Permian, but on land the state was home to thousands of different insect species. The popular pterosaur "Pteranodon" is best known from this state. During the early part of the Cenozoic era Kansas became a savannah environment. Later, during the Ice Age, glaciers briefly entered the state, which was home to camels, mammoths, mastodons, and saber-teeth. Local fossils may have inspired Native Americans to regard some local hills as the homes of sacred spirit animals. Major scientific discoveries in Kansas included the pterosaur "Pteranodon" and a fossil of the fish "Xiphactinus" that died in the act of swallowing another fish.
Pteranodon longiceps would have shared the sky with the giant-crested pterosaur Nyctosaurus. Compared to P. longiceps, which was a very common species, Nyctosaurus was rare, making up only 3% of pterosaur fossils from the formation. Also less common was the early toothed bird, Ichthyornis.[16]
Two species of Pteranodon are traditionally recognized as valid: Pteranodon longiceps, the type species, and Pteranodon sternbergi. The species differ only in the shape of the crest in adult males (described above), and possibly in the angle of certain skull bones.[6] Because well-preserved Pteranodon skull fossils are extremely rare, researchers use stratigraphy (i.e. which rock layer of the geologic formation a fossil is found in) to determine species identity in most cases.