PixlBit

WARNING! This is from Wikipedia. Son it might have been edited. This do to there not being much in the way of in depth information on it, that is reliable.

PTERANODON

Kingdom: Animalia
Phylum: Chordata
Order: Pterosauria
Family: Pteranodontidae
Subfamily: Pteranodontinae
Marsh, 1876
Genus: Pteranodon
Type species
Pteranodon longiceps
Marsh, 1876
Other species

P. sternbergi
Harksen, 1966

Synonyms

Occidentalia Miller, 1972
Geosternbergia? Miller, 1978
Longicepia Miller, 1978
Dawndraco? Kellner, 2010

http://www.evolutionswitness.com/…/…/2011/08/pteranodon3.jpg

http://pterosaur.net/popular_culture/pteranodon_jplw.jpg

Pteranodon (/t??ræn?d?n/; from Greek πτερ?ν ("wing") and ?ν?δων ("toothless")) is a genus of pterosaurs which included some of the largest known flying reptiles, with wingspans over 6 metres (20 ft). It existed 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.

Pteranodon was not a dinosaur. By definition, all dinosaurs belong to the groups Saurischia and Ornithischia, which exclude pterosaurs. Nevertheless, Pteranodon is frequently featured in dinosaur books and is strongly associated with dinosaurs by the general public.

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 information on the anatomy of the animal. 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.

Size of P. longiceps male (green) and female (orange) compared with a human

http://upload.wikimedia.org/…/com…/f/fc/Pteranodon_scale.png

Adult Pteranodon specimens from the two major species can be divided into two distinct size classes. The smaller class of specimens have small, rounded head crests and very wide pelvic canals, even wider than those of the much larger size class. The size of the pelvic canal probably allowed the laying of eggs, indicating that these smaller adults are females. The larger size class, representing male individuals, have narrow hips and very large crests, which were probably for display.

Adult male Pteranodon were among the largest pterosaurs, and were the largest flying animals known until the late 20th century, when the giant azhdarchid pterosaurs were discovered. The wingspan of an average adult male Pteranodon was 5.6 metres (18 ft). Adult females were much smaller, averaging 3.8 metres (12 ft) in wingspan. The largest specimen of Pteranodon longiceps from the Niobrara Formation measured 6.25 metres (20.5 ft) from wingtip to wingtip. An even larger specimen is known from the Pierre Shale Formation, with a wingspan of 7.25 metres (23.8 ft), though this specimen may belong to the distinct genus and species Geosternbergia maysei. While most specimens are found crushed, enough fossils exist to put together a detailed description of the animal.

Methods used to estimate the weight of large male Pteranodon specimens (those with wingspans of about 7 meters) have been notoriously unreliable, producing a wide range of estimates from as low as 20 kilograms (44 lb) and as high as 93 kilograms (205 lb). In a review of pterosaur size estimates published in 2010, researchers Mark Witton and Mike Habib demonstrated that the latter, largest estimates are almost certainly incorrect given the total volume of a Pteranodon body, and could only be correct if the animal "was principally comprised of aluminium."Witton and Habib considered the methods used by researchers who obtained smaller weight estimates equally flawed. Most have been produced by scaling modern animals such as bats and birds up to Pteranodon size, despite the fact that pterosaurs have vastly different body proportions and soft tissue anatomy from any living animal.

Skull and beak

http://upload.wikimedia.org/…/40/Pteranodon_sp_AMNH_7515.jpg

Unlike earlier pterosaurs such as Rhamphorhynchus and Pterodactylus, Pteranodon had toothless beaks, similar to those of modern birds. Pteranodon beaks were made of solid, bony margins that projected from the base of the jaws. The beaks were long, slender, and ended in thin, sharp points. The upper jaw was longer than the lower jaw. The upper jaw was curved upward; while this normally has been attributed only to the upward-curving beak, one specimen (UALVP 24238) has a curvature corresponding with the beak widening towards the tip. While the tip of the beak is not known in this specimen, the level of curvature suggests it would have been extremely long. The unique form of the beak in this specimen lead Alexander Kellner to assign it to a distinct genus, Dawndraco, in 2010.

The most distinctive characteristic of Pteranodon is its cranial crest. These crests consisted of skull bones (frontals) projecting upward and backward from the skull. The size and shape of these crests varied due to a number of factors, including age, sex, and species. Male Pteranodon sternbergi, the older species of the two described to date (and sometimes placed in the distinct genus Geosternbergia), had a more vertical crest with a broad forward projection, while their descendants, Pteranodon longiceps, evolved a narrower, more backward-projecting crest. Females of both species were smaller and bore small, rounded crests. The crests were probably mainly display structures, though they may have had other functions as well.

Skeleton

Other distinguishing characteristics that set Pteranodon apart from other pterosaurs include narrow neural spines on the vertebrae, plate-like bony ligaments strengthening the vertebrae above the hip, and a relatively short tail in which the last few vertebrae are fused into a long rod. The entire length of the tail was about 3.5% as long as the wingspan, or up to 25 centimetres (9.8 in) in the largest males.

Timespan and evolution

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. The genus is present in most layers of the Niobrarra 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.

In the early 1990s, Bennett noted that the two major morphs of pteranodont present in the Niobrara Formation were precisely separated in time with little, if any, overlap. Due to this, and to their gross overall similarity, he suggested that they probably represent chronospecies within a single evolutionary lineage lasting about 4 million years. In other words, only one species of Pteranodon would have been present at any one time, and P. sternbergi (or Geosternbergia) in all likelihood was the direct ancestor species of P. longiceps.

Biology and ecology

Range and environment

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.

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. 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.

http://upload.wikimedia.org/…/co…/2/25/Cretaceous_seaway.png

http://upload.wikimedia.org/…/Pteranodon_longiceps_mmartyni…

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.

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.

Below the surface, the sea was populated primarily by invertebrates such as ammonites and squid. Vertebrate life, apart from basal fish, included sea turtles such as Toxochelys, the plesiosaur Styxosaurus, and the flightless diving bird Parahesperornis. Mosasaurs were the most common marine reptiles, with genera including Clidastes and Tylosaurus. At least some of these marine reptiles are known to have fed on Pteranodon. Barnum Brown, in 1904, reported plesiosaur stomach contents containing "pterodactyl" bones, most likely from Pteranodon.

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).

Flight

http://upload.wikimedia.org/wikipedia/…/0/05/Quad_launch.jpg

The wing shape of Pteranodon suggests that it would have flown rather like a modern-day albatross. This is based on the fact that Pteranodon had a high aspect ratio (wingspan to chord length) similar to that of the albatross — 9:1 for Pteranodon, compared to 8:1 for an albatross. Albatrosses spend long stretches of time at sea fishing, and use a flight pattern called "dynamic soaring" which exploits the vertical gradient of wind speed near the ocean surface to travel long distances without flapping, and without the aid of thermals (which do not occur over the open ocean the same way they do over land). While most of a Pteranodon flight would have depended on soaring, like long-winged seabirds, it probably required an occasional active, rapid burst of flapping, and studies of Pteranodon wing loading (the strength of the wings vs. the weight of the body) indicate that they were capable of substantial flapping flight, contrary to some earlier suggestions that they were so big they could only glide.

Like other pterosaurs, Pteranodon probably took off from a standing, quadrupedal position. Using their long forelimbs for leverage, they would have vaulted themselves into the air in a rapid leap. Almost all of the energy would have been generated by the forelimbs. The upstroke of the wings would have occurred when the animal cleared the ground followed by a rapid down-stroke to generate additional lift and complete the launch into the air.

Diet

The diet of Pteranodon is known to have included fish; fossilized fish bones have been found in the stomach area of one Pteranodon, and a fossilized fish bolus has been found between the jaws of another Pteranodon, specimen AMNH 5098. Numerous other specimens also preserve fragments of fish scales and vertebrae near the torso, indicating that fish made up a majority of the diet of Pteranodon (though they may also have taken invertebrates).

Traditionally, most researchers have suggested that Pteranodon would have taken fish by dipping their beaks into the water while in low, soaring flight. However, this was probably based on the assumption that the animals could not take off from the water surface. It is more likely that Pteranodon could take off from the water, and would have dipped for fish while swimming rather than while flying. Even a small, female Pteranodon could have reached a depth of at least 80 centimetres (31 in) with its long bill and neck while floating on the surface, and they may have reached even greater depths by plunge-diving into the water from the air like some modern long-winged seabirds. In 1994, Bennett noted that the head, neck, and shoulders of Pteranodon were as heavily built as diving birds, and suggested that they could dive by folding back their wings like the modern Gannet.

For more information, go here-

http://en.wikipedia.org/wiki/Pteranodon