PTERANODON
Updated 04-May-2020.
Mondo shtuff from around the internet, all about PTERANODON!
My botty best at summarizing from Wikipedia: genus of pterosaur includes some of the largest known flying reptiles . they lived during the late Cretaceous geological period of north America . more fossil specimens of Pterano over 1,000 specimens have been identified, though less than half are complete enough to give researchers good anatomical information . pterosaurs such as Pteranodon form a sister clade to dinosaurs adult male 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 . adult the wingspan of an average adult male Pteranodon was 5.6 metres (18 ft) adult females were much smaller, averaging 3.8 metres (12 f) in wingspan . the largest specimen of P methods used to estimate mass of large male Pteranodon specimens have been notoriously unreliable . estimates range from as low as 20 kilograms (44 lb) to as high as 93 kilograms . the unique form of the beak in this specimen led Alexander Kellner to assign it to a distinct genus, Dawndraco, in 2010 . the most distinctive characteristic of Pteranodon is its cranial the size and shape of these crests varied due to a number of factors, including age, sex, and species . male Pteranodon sternbergi had a more vertical crest with a albatrosses use a flight pattern called “dynamic soaring” pteranodon had a high aspect ratio (wingspan to chord length) similar to that of the albatross . studies of the possibility of aquatic locomotion via swimming has been discussed briefly . Numerous other specimens also preserve fragments of fish scales and vertebrae near the torso . this indicates that fish made up a majority of in 1994, Bennett noted that the head, neck, and shoulders of Pteranodon were as heavily built as diving birds . he suggested that they could dive by folding back their wings like the modern gannet . most Bennett (1992) agreed with Eaton’s own assessment that the crest was too large and variable . Eaton had suggested a secondary function might have been as a counterbalance against the long beak . wind tunnel in 1943, dominik von Kripp suggested that the crest may have served as a rudder . one researcher even suggested that it may have supported a membrane of skin connecting the backward-pointing crest to the best-supported hypothesis for crest function seems to be as a sexual display . females and juveniles have small crests and males large, elaborate, variable crest . both size classes lived alongside each other . some larger skulls show evidence of a second crest that extended long and low, toward the tip of the beak . the smaller size class had disproportionately large and wide-set pelvic bones . Bennett interpreted this females seem to have outnumbered males two to one, suggesting a polygynous animal . crests of male Pteranodon would not have been used in competition . males played little to no part Pteranodon fossils have only been found in the southern half of the formation . no pterosaur specimens have ever been found there . compared to P. longiceps, Nyctosaurus was rare, making up only 3% of fossils . also less common was the early toothed bird, Ichthyornis . fossils from terrestrial dinosaurs also have been found in the Niobrara Chalk . one specimen of a hadrosaur appears to have been scavenged by a shark . ypm 1160 and 1161 consisted of partial wing bones and a tooth from a prehistoric fish . in 1871, Marsh named the find “Pterodactylus oweni” Cope’s paper naming his species was published in 1872, just five days after Marsh’s . this resulted in a dispute over whose names had priority in the same species . Cope conceded in the skulls showed that the north american pterosaurs were different from any European species . Marsh recognized this major difference, coined the name Pteranodon (“wing without tooth”) in 1876 . Marsh classified the larger skull in the new species Pteranodon longiceps . he also named several additional species: Pterans comptus and nanus . in 1892, Samuel Williston examined he noticed that Seeley had mentioned a partial set of toothless pterosaur jaws he named “Ornithostoma” in 1871 . williston concluded “ornit ornithostoma may have been an azhdarchoid, a different type of toothless pterosaur . he agreed with most of Marsh’s classification, with in 1910, Eaton became the first scientist to publish a more detailed description of the entire Pteranodon skeleton . he used his findings to revise the classification of the genus once again based Eaton recognized only three valid species: P. occidentalis, P. ingens, and P. longiceps . Miller concluded that all Pteranodon species except two based on skulls must be considered nom Miller created three categories or “subgenera” for tangle of names . the subgenus Longicepia was later changed to simply Pteranodon due to rules of priority . Miller also expanded the concept Miller considered these to be an evolutionary progression . he made several mistakes in his study concerning which specimens he assigned to which species . the genus is present in most layers of the Niobrara Formation except for a possible third species is known from the Pierre Shale Formation dating to between 81.5 and 80.5 million years ago . in the early 1990s, Bennett noted that the two major morphs of pteranodont researchers use stratigraphy to determine species identity in most cases . because well-preserved Pteranodon skull fossils are extremely rare, stratigraphic analysis is used . the lower jaw of P. stern phylogenetic placement of this genus within Pteranodontia from andres and myers (2013) . classification of two forms has varied from researcher to researcher . in 1978 Miller re-named the species Pteranodon (Geosternbergia) sternberga . in 2010, pterosaur researcher Alexander Kellner revisited Miller’ Kellner argued that the specimen’s crest was most similar to Geosternbergia . because the specimen was millions of years younger than any known species, he assigned it to a new species . Kell other valid species include the possibly larger P. sternbergi, with a wingspan originally estimated at 9 m (30 ft) all probably are synonymous with the more well-known species . because the key distinguishing characteristic the name became a wastebasket taxon to label any pterosaur remains that could not be distinguished other than by the absence of teeth . Species have been reclassified a number of times