Pteranodon (pronounced /tɨˈrænədɒn/; from Greek πτερ- "wing" and αν-οδων "toothless"), from the Late Cretaceous of North America (Kansas, Alabama, Nebraska, Wyoming, and South Dakota), was one of the largest pterosaur genera, with a wingspan of up to 9 metres (30 ft). Pteranodon is known from more fossil specimens than any other pterosaur, with about 1,200 specimens known to science, many of them well preserved with complete skulls and articulated skeletons, and was an important part of the animal community present in the Western Interior Seaway.[1]
Pteranodon was a reptile, but not a dinosaur. All dinosaurs are diapsid reptiles with an upright stance, and by definition Dinosauria consists of the groups Saurischia and Ornithischia, which excludes Pterosauria. While the advanced pterodactyloid pterosaurs like Pteranodon had a semi-upright stance, this evolved independently of the upright stance in dinosaurs, and pterosaurs lacked the distinctive adaptations in the hip associated with the dinosaurian posture. However, dinosaurs and pterosaurs may have been closely related, and most paleontologists place them together in the group Ornithodira, or "bird necks".
Description[]

Life restoration of an adult male P. longiceps in flight

Skeleton of an adult male P. longiceps
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 short tail in which the last few vertebrae are fused into a rod.[2]
There are two species of Pteranodon currently 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.[2]
Pteranodon fossils are known from the Niobrara and Pierre Formations of the central United States. Pteranodon existed as a group for over four million years during the late Coniacian - early Campanian stages of the Cretaceous period.[2] It 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 88-85 million years ago, while P. longiceps existed between 86-84.5 million years ago. A possible third species 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.[3]
Size[]
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.

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

Skull and beak of specimen AMNH 7515
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. This led Bennett (1994) to suggest that the upward curve was not entirely due to a curved beak, but rather indicated an Anhanguera-like sloping crest on the front of the beak (premaxilla). However, further specimens would be necessary to determine the actual structure of the beak in P. sternbergi. Some specimens of both P. sternbergi and P. longiceps do preserve the beak tips, and lack any premaxillary crests.[2]
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.
Classification[]

Skeleton of P. longiceps, in launch pose, Telus World of Science, Vancouver
Species[]
A number of species of Pteranodon have been named since the 1870s, though most are now considered to be junior synonyms of two or three valid species. The best-supported is the type species, P. longiceps, based on a well-preserved specimen including the first-known skull found by S.W. Williston. This individual had a wingspan of 7 mteres.[4] Other valid species include the possibly larger P. sternbergi, with a wingspan originally estimated at 9 metres.[4] P. occidentalis, P. velox, P. umbrosus, P. harpyia and P. comptus are considered to be nomina dubia by Bennett (1994) and others. All are probably synonymous with the more well-known Pteranodonspecies.

Mounted skeleton at the Museum of Ancient Life
Pteranodon sternbergi is the only known species of Pteranodon with an upright-crest. The lower jaw of P. sternbergi was 1.25 meters (4 ft) long.[5] It 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 P. longiceps and is considered by Bennett to be the direct ancestor of the later species.[2]

Variation in cranial anatomy and classification of specimens assigned to Pteranodon (drawn to scale, unpreserved portions shown in gray)
Pteranodon existed for ~4 million years, from the Early Coniacian to the Early Campanian, found in most of the Niobrara excluding the uppermost 2. P. sternbergi existed from 88-85 million years ago and P. longiceps from 86-84.5 million years ago, as found by Kenneth Carpenter (2003). Two likely chronospecies are known in a single lineage lasting 4 million years; only one species would have been present at once, with P. sternbergi a likely ancestor species to P. longiceps. Andres and Myers (2013) conclude:
Pteranodontia |
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Alternative classifications[]

P. occidentalis mount wherein arms, shoulder girdle, and fingers are actual bones, and the rest has been drawn from other specimens.
Because of the subtle variations among the Niobrara Formation pteranodontids, many researchers have assigned them all to the single genus Pteranodon , with at least two species ( P. longiceps and P. sternbergi ) distinguished largely by the shape of their crests. However, the classification of these two forms has varied from researcher to researcher. In 1972, Halsey Wilkinson Miller published a paper arguing that the various forms of Pteranodon were sufficiently distinct to be placed in separate subgenera. He named them Pteranodon (Occidentalia) occidentalis (for the now-disused species P. occidentalis ) and Pteranodon (Sternbergia) sternbergi . However, the name Sternbergia had already been used, and in 1978 Miller renamed the species Pteranodon (Geosternbergia) sternbergi , and named a third subgenus–species combination for P. longiceps , Pteranodon (Longicepia) longiceps . Many prominent pterosaur researchers of the late 20th century, including S. Christopher Bennett and Peter Wellnhofer, however, did not accept these subgeneric names, and continued to place all pteranodont species in the genus Pteranodon.
In 2010, pterosaur researcher Alexander Kellner revised H. W. Miller's classification. Kellner followed Miller's view that the differences between Pteranodon species were great enough to warrant placing them in separate genera. He thus placed P. sternbergi in Miller's named genus Geosternbergia , along with the Pierre Shale cranial specimen that Bennett had previously regarded as a large male P. longiceps . Kellner stated that the specimen's crest, although incompletely preserved, was most similar to that of Geosternbergia . Since the specimen was millions of years younger than any known Geosternbergia , he assigned it to the new species Geosternbergia maysei . Numerous specimens of pteranodonts are known from the same formation and time period, and Kellner suggested that they might belong to the same species as G. maysei , but since they lack skulls, he could not identify them with certainty.
Dubious species[]

S.W. Williston's reconstruction of Ornithostoma ingens, a synonym of P. longiceps
A number of additional species of Pteranodon have been named since the 1870s, although many are now considered younger synonyms of the two or three valid species. The best known is the type species, P. longiceps , based on well-preserved specimens including the first known skull found by S. W. Williston. This individual had a wingspan of 7 m. Other valid species include the possibly larger P. sternbergi , with a wingspan originally estimated at 9 m. P. occidentalis , P. velox , P. umbrosus , P. harpyia , and P. comptus were considered nomina dubia by Bennett (1994) and others who questioned their validity. They are probably all synonyms of the better-known species.
Because the key distinguishing characteristic Marsh noted for Pteranodon was its lack of teeth, any toothless pterosaur jaw fragment, wherever it was found in the world, tended to be attributed to Pteranodon during the late 19th and early 20th centuries. This resulted in a plethora of species and a great deal of confusion. The name became a wastebasket taxon, rather like the dinosaur Megalosaurus, to label any pterosaur remains that could not be distinguished other than by the absence of teeth. Species (often dubious ones now known to be based on sexual variation or juvenile characters) have been reclassified a number of times, and several sub-genera were erected in the seventies by Halsey Wilkinson Miller to hold them in various combinations, further confusing the taxonomy (subgenera include Longicepia, Occidentalia, and Geosternbergia). Notable authors who have discussed the various aspects of Pteranodon include Bennett, Padian, Unwin, Kellner, and Wellnhofer. Two species, P. orogensis and P. orientalis, are not actually pteranodontids and have been renamed Bennettazhia oregonensis and Bogolubovia orientalis respectively.
List of species and synonyms[]
Status of names listed below follow a survey by Bennett, 1994 unless otherwise noted.[2]
Name | Author | Year | Status | Notes |
---|---|---|---|---|
Pterodactylus occidentalis | Marsh | 1872 | Reclassified as Pteranodon occidentalis | Reclassified from Pterodactylus oweni Marsh 1871 (preoccupied by Seeley 1864) |
Pterodactylus ingens | Marsh | 1872 | Reclassified as Pteranodon ingens | |
Pterodactylus velox | Marsh | 1872 | Nomen dubium | Reclassified as Pteranodon velox |
Ornithochirus umbrosus | Cope | 1872 | Nomen dubium | |
Ornithochirus harpyia | Cope | 1872 | Nomen dubium | |
Pterodactylus umbrosus | (Cope) Cope | (1872) 1874 | Reclassification of Ornithochirus umbrosus | |
Pteranodon longiceps | Marsh | 1876 | Valid | Type species |
Pteranodon ingens | (Marsh) Williston | (1872) 1876 | Nomen dubium | Reclassified from Pterodactylus ingens |
Pteranodon occidentalis | Marsh | (1872) 1876 | Nomen dubium | Reclassified from Pterodactylus occidentalis |
Pteranodon velox | Marsh | (1872) 1876 | Nomen dubium | Reclassified from Pterodactylus velox, based on a juvenile specimen |
Pteranodon gracilis | Marsh | 1876 | Reclassified as Nyctosaurus gracilis | |
Pteranodon comptus | Marsh | 1876 | Nomen dubium | |
Pteranodon nanus | Marsh | 1876 | Reclassified as Nyctosaurus nanus | |
Ornithocheirus umbrosus | (Cope) Newton | (1872) 1888 | Reclassified as Pteranodon umbrosus | Spelling correction of Ornithochirus umbrosus |
Ornithocheirus harpyia | (Cope) Newton | (1872) 1888 | Reclassified as Pteranodon harpyia | Spelling correction of Ornithochirus harpyia |
Pteranodon umbrosus | (Cope) Williston | (1872) 1892 | Nomen dubium | Reclassification of Ornithochirus umbrosus |
Ornithostoma ingens | (Marsh) Williston | (1872) 1893 | Synonym of Pteranodon ingens | Reclassified from Pteranodon ingens |
Ornithostoma umbrosum | (Cope) Williston | (1872) 1897 | Synonym of Pteranodon umbrosus | Reclassified from Pteranodon umbrosus |
Pteranodon oregonensis | Gilmore | 1928 | Reclassified as Bennettazhia oregonensis | |
Pteranodon sternbergi | Harksen | 1966 | Valid | |
Pteranodon marshi | Miller | 1972 | Synonym of Pteranodon longiceps | |
Pteranodon bonneri | Miller | 1972 | Reclassified as Nyctosaurus bonneri | |
Pteranodon walkeri | Miller | 1972 | Synonym of Pteranodon longiceps | |
Pteranodon (Occidentalia) eatoni | (Miller) Miller | (1972) 1972 | Synonym of Pteranodon sternbergi | |
Pteranodon eatoni | (Miller) Miller | (1972) 1972 | Synonym of Pteranodon sternbergi | Reclassified from Pteranodon (Occidentalia) eatoni |
Pteranodon (Longicepia) longicps [sic] | (Marsh) Miller | (1872) 1972 | Synonym of Pteranodon longiceps | Reclassified from Pteranodon longiceps |
Pteranodon (Longicepia) marshi | (Miller) Miller | (1972) 1972 | Synonym of Pteranodon longiceps | Reclassified from Pteranodon marshi |
Pteranodon (Sternbergia) sternbergi | (Harksen) Miller | (1966) 1972 | Reclassified as Pteranodon (Geosternbergia) sternbergi | Reclassified from Pteranodon sternbergi |
Pteranodon (Sternbergia) walkeri | (Miller) Miller | (1972) 1972 | Reclassified as Pteranodon (Geosternbergia) walkeri | Reclassified from Pteranodon walkeri |
Pteranodon (Pteranodon) marshi | (Miller) Miller | (1972) 1973 | Synonym of Pteranodon longiceps | Reclassified from Pteranodon marshi |
Pteranodon (Occidentalia) occidentalis | (Marsh) Olshevsky | (1872) 1978 | Synonym of Pteranodon occidentalis | Reclassified from Pteranodon occidentalis |
Pteranodon (Longicepia) ingens | (Marsh) Olshevsky | (1872) 1978 | Synonym of Pteranodon ingens | Reclassified from Pteranodon ingens |
Pteranodon (Pteranodon) ingens | (Marsh) Olshevsky | (1872) 1978 | Synonym of Pteranodon ingens | Reclassified from Pteranodon ingens |
Pteranodon (Geosternbergia) walkeri | (Miller) Miller | (1972) 1978 | Synonym of Pteranodon longiceps | Reclassified from Pteranodon walkeri |
Pteranodon (Geosternbergia) sternbergi | (Harksen) Miller | (1966) 1978 | Synonym of Pteranodon sternbergi | Reclassified from Pteranodon (Sternbergia) sternbergi |
Pteranodon orientalis | (Bogolubov) Nesov & Yarkov | (1914) 1989 | Reclassified as Bogolubovia orientalis | Reclassified from Ornithostoma orientalis |
Geosternbergia walkeri | (Miller) Olshevsky | (1872) 1991 | Synonym of Pteranodon sternbergi | Reclassified from Pteranodon (Sternbergia) walkeri |
Geosternbergia sternbergi | (Harksen) Olshevsky | (1966) 1991 | Synonym of Pteranodon sternbergi | Reclassified from Pteranodon (Geosternbergia) sternbergi |
History of discovery[]
Pteranodon was the first pterosaur found outside of Europe. Its fossils were first found by Othniel Charles Marsh in 1870, in the Late Cretaceous Smoky Hill Chalk 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 is now 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 his new pterosaur (all known pterosaurs up to that point had teeth). In 1871, Marsh named the find Pterodactlyus 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 Pterodactylus oweni had in 1864 already been used for a specimen of the European Pterodactylus, Marsh re-named his North American pterosaur Pterodactylus occidentalis, or "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 Pterodactlyus velox (the smallest).[2]

Early illustration of "Ornithochirus umbrosus" (now Pteranodon longiceps), when teeth were erroneously attributed to the species and the crest was unknown, 1872
Meanwhile, Marsh's rival Edward Drinker Cope had also unearthed several specimens of the large North American pterosaur. Based on these specimens, Cope named two new species, Ornithochirus umbrosus and Ornithochirus harpyia, in an attempt to assign them to the large European genus Ornithocheirus. However, as he misspelled the name (forgetting the 'e'), he accidentally created an entirely new genus.[2] Cope's paper naming his ''Ornithochirus species was published in 1872, just five days after Marsh's paper. This resulted in a dispute, fought in the published literature, over whose names had priority in what were obviously the same species.[2] Cope conceded in 1875 that Marsh's names did have priority over his, but maintained that Pterodactylus umbrosus was a distinct species (but not genus) from any that Marsh had named previously.[6] Re-evaluation by later scientists has supported Marsh's case, and found that Cope's assertion that P. umbrosus was a larger, distinct species were wrong.[2]

Short-crested P. longiceps holotype specimen YPM1177, now interpreted as a female individual

Historical skeletal reconstruction of P. longiceps, 1914
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 followed. These skulls showed that the North American pterosaur was different than any European species, in that they lacked teeth. Marsh recognized that 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 warranted a new genus, and he coined the name Pteranodon ("wing without tooth") in 1876. Marsh also reclassified all the previously named North American species from Pterodactylus to Pteranodon, with the larger skull, YPM 1117, referred to the new species Pteranodon longiceps.[7] He also named an additional species, Pteranodon gracilis, based on a wing bone that he mistook for a pelvic bone. He realized his mistake, and re-classified this specimen in a separate genus, which he named Nyctosaurus.[8]
Some of the most influential studies on Pteranodon during the 20th century were published by George Francis Eaton, who conducted the reanalysis of the known specimens and published some of the first quality photographs and illustrations of the best specimens. In the early 1990s, S. Christopher Bennett also published several important papers reviewing the anatomy, taxonomy, and life history of Pteranodon .
Paleobiology[]
Diet[]

Fish remains between the jaws of specimen AMNH 5098
The diet of Pteranodon is known to have included fish; Fossil fish bones have been found in abdominal cavities and a bolus was found between the jaws of AMNH 5098. Others preserve fish scales and vertebrae associated with the torso; thus, it is assumed fish comprise most of Pteranodon's diet, though it may have occasionally snacked on invertebrates. It is most often suggested to have fed to skimming while flying near-to the water's surface, which was assumed from the idea that they were unable to take flight from the water. However, the contrary is likely. It probably landed in water, snatching a few fish by dipping its beak under while swimming, and then taking flight. A small female could reach at least 80 centimeters (31 inches) in depth with the beak alone, reaching even deeper by plunge-diving from the air like most long-winged seabirds. Bennett notes the head, neck and shoulders are as heavily built as diving birds, probably diving by folding their wings like a gannet.
Flight[]

Artist's impression of P. sternbergi

Skeletal reconstruction of a quadrupedally launching male P. longiceps
The wing shape of Pteranodon suggests that it would have flown rather like a modern-day albatross. This is a suggestion based on the fact that the 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 utilize 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).[9] However, most scientists do agree that Pteranodon could flap their wings and fly with power. These two flight styles would not have been mutually exclusive in Pteranodon, or in pterosaurs in general. It would have had to soar, having a rapid burst of flapping (of which it could sustain a substantial amount). One recent study suggests it relies on thermal soaring much like continental flyers and Pelagornis. It took flight from a standing position, using their forelimbs as leverage to leap into the air via a high amount of generated energy. The wings would upstroke once the animal was a considerable distance from the ground, which was followed by a rapid downstroke that generated more lift, launching the animal into the air.
Like other pterosaurs, Pteranodon probably took off from a quadrupedal position. Using its large limbs for leverage, it would have propelled itself into the air in a quick leap. Almost all of the power would have been generated by the wings themselves. The upward stroke of the wings would have occurred when the animal had prepared the ground followed by a rapid descent to generate the additional lift and complete the launch into the air.
Crest[]

Putative male Pteranodon longiceps specimens YPM 2594 and 2493
Pteranodon was notable for its skull crest, though the function of the crest has been a subject of debate. However, most explanations have focused on the blade-like, backward pointed crest of male P. longiceps, and ignored the wide range of variation across age and gender. The fact that the crests vary so much rules out most practical functions other than for use in mating displays.
George Francis Eaton, in 1910, proposed two possible functions for the crest: as an aerodynamic counterbalance, and as a muscle attachment point. He suggested that the crest might have anchored large, long jaw muscles, but admitted that this function alone could not explain the large size of some crests.[10] Bennett (1992) agreed with Eaton's own assessment that the crest was too large and variable to have been a muscle attachment site.[11] Eaton had suggested that a secondary function of the crest might have been as a counterbalance against the long beak, reducing the need for heavy neck muscles to control the orientation of the head.[10] Wind tunnel tests showed that the crest did function as an effective counterbalance to a degree, but Bennett noted that the hypothesis again focuses only on the long crests of male P. longiceps, not on the larger crests of P. sternbergi and very small crests of females. Bennett found that the crests of females had no counterbalancing effect, and that the crests of male P. sternbergi would, by themselves, have a negative effect on the balance of the head. Side to side movement of the crests would actually have required more, not less, neck musculature to control.[11]
In 1943, Dominik von Kripp suggested that the crest may have served as a rudder, an idea embraced by several later researchers.[11][12] One researcher, Ross S. Stein, even suggested that the crest may have supported a membrane of skin connecting the backward-pointing crest to the neck and back, increasing its surface area and effectiveness as a rudder.[13] The rudder hypothesis again does not take into account females or P. sternbergi, which had an upward-pointing, not backward-pointing crest. Bennett also found that even in its capacity as a rudder, the crest would not provide nearly as much directional force as simply maneuvering the wings. The suggestion that the crest was an air brake, and that the animals would turn their heads to the side in order to slow down, suffers from a similar problem.[14] Additionally, the rudder and air brake hypotheses do not explain why such large variation exists in crest size even among adults.[11]
Alexander Kellner suggested that the large crests of the pterosaur Tapejara, as well as other species, might be used for heat exchange, allowing these pterosaurs to absorb or shed heat and regulate body temperature, which would also account for the correlation between crest size and body size. However, there is no evidence of extra blood vessels in the crest for this purpose, and the large, membranous wings filled with blood vessels would have served that purpose much more effectively.[11]
With the above 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 juveniles and females have small crests and males large, elaborate, variable crests.[11]
Sexual variation[]

Skeletal reconstruction of a female P. longiceps
Adult Pteranodon specimens can be divided into two distinct size classes, small and large, with the large size class being about one and a half times larger than the small, and the small being twice as common as the large. Both size classes lived along side each other, and while researchers had previously suggested that they represent different species, Christopher Bennett showed that the differences between them are consistent with the idea that they represent males and females, and that Pteranodon species were sexually dimorphic. Skulls from the larger size class preserve large, upwards and backward pointing crests, while the crests of the smaller size class are small and triangular. Some larger skulls also show evidence of a second crest that extended long and low along toward the tip of the beak, which is not seen in smaller specimens.[11]
The sex of the different size classes was determined not from the skulls, but from the pelvic bones. Contrary to what may be expected, the smaller size class had disproportionately large and wide-set pelvic bones. Bennett interpreted this as indicating a more spacious birth canal, through which eggs would pass. He concluded that the small size class with small, triangular crests represent females, and the larger, large-crested specimens are male.[11]
Note that the overall size and crest size also corresponds to age. Immature specimens are known from both females and males, and immature males often have small crests similar to adult females. Therefore, it seems that the large crests only developed in males when they reached their large, adult size, making the sex of immature specimens difficult to establish from partial remains.[15]
The fact that females appear to have outnumbered males two to one suggests that, like modern animals with size-related sexual dimorphism such as sea lions and other pinnipeds, Pteranodon were polygynous, with a few males presiding over, and competing for, large numbers of females. Like modern pinnipeds, Pteranodon may have fought 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. It is also 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.[11]
Locomotion[]
The terrestrial locomotion of Pteranodon, especially whether it was bipedal or quadrupedal, has historically been the subject of debate. Today, most pterosaur researchers agree that pterosaurs were quadrupedal, thanks largely to the discovery of several pterosaur trackways. The possibility of swimming has been discussed briefly in two papers (Bennett 2001 and Bramwell & Whitfield 1974), and has been studied in detail at Michigan State University through the use of quantitative morphometrics and an extant phylogenetic bracket (a morphologically comparative technique invented by Larry Witmer).[14][16]
Paleoecology[]

Map of North America during the mid-Cretaceous period, illustrating the Western Interior Seaway (middle to upper left) and other nearby seaways
Specimens assigned to Pteranodon have been found in both the Smoky Hill Chalk deposits of the Niobrara Formation, and in the slightly younger deposits of the Pierre Shale Formation. When Pteranodon lived, this area was covered by a large inland sea, known as the Niobrara Sea. Famous for fossils found since 1870, these formations extend from as far south as Kansas in the United States to Manitoba in Canada. However, specimens of Pteranodon (or any pterosaur) 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 contemporary parts of the formation in Canada, no pterosaur specimens have been found there. This strongly suggests that Pteranodon 's natural geographic range covered only the southern part of the Niobrara Sea, and that its habitat did not extend farther north than South Dakota.
Very fragmentary fossils belonging to pteranodont pterosaurs, and possibly Pteranodon itself , have also been found on the Gulf Coast and East Coast of the United States. For example, bone fragments from the Mooreville Formation of Alabama and the Merchantville Formation of Delaware may belong to Pteranodon , although they are too incomplete to make a definitive identification. Some remains from Japan have been tentatively attributed to Pteranodon , but their distance from the Niobrara Sea habitat makes such an identification unlikely.

Pteranodon specimen with a Cretoxyrhina tooth embedded in a neck vertebra
Pteranodon longiceps may have shared the skies with the crested pterosaur Nyctosaurus . Compared to P. longiceps , which was a very common species, Nyctosaurus was rare, accounting for only 3% of the pterosaur fossils from the formation. Even rarer was the primitive toothed bird Ichthyornis .
Like other polygynous animals (in which males compete for harems of females), Pteranodon probably lived primarily on rocky coasts, where they could nest away from land predators and feed far from shore; many Pteranodon fossils have been found in places that were, at that time, hundreds of miles from the coastline.
Below the surface, the sea was populated primarily by invertebrates such as ammonites and squid. Vertebrates, apart from primitive 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 such as Clidastes and Tylosaurus . At least some of these marine reptiles are known to have fed on Pteranodon . Barnum Brown in 1904 reported that the contents of the stomach area of a plesiosaur contained bones of a "pterodactyl", most likely Pteranodon .
Dinosaur fossils have also been found in the Niobrara Limestone, suggesting that animals that died on the coast must have been washed out to sea (one specimen of a hadrosaur appears to have been eaten by a shark).
JPInstitute.com Description[]
First thing, Pteranodon is not a dinosaur, it is a flying reptile. A really big flying reptile! When it spread its wings, it could reach from the front to the back of a school bus. Just imagine something that big flying around. It didn't have feathers, but it may have had a covering of fur, sort of like a bat.
Members of the pterosaur family lived through much of the Mesozoic, some with wingspans close to 50 feet. Pteranodon, as you can tell by the translation of its name, had no teeth. It probably used the long crest on the back of its head to help it steer while flying. There is still some debate about whether these reptiles could actually fly or if they were primarily gliders, but the consensus seems to be that they could take off with little or no wind.
Their diet was probably fish and scavenged remains of dead animals. Quite a few Pteranodon skeletons have been found in Kansas in the central part of the U.S. This would have been the shore of a shallow sea when these creatures were alive, supporting the theory that they were fish eaters.
Dinosaur Field Guide Description[]
Pteranodon ("wings without teeth') is probably the best known of the more advanced pterosaurs, called pterodactyls ("winged fingers"). There are several species of Pteranodon, each with a distinctive crest on the back of the head. All species of Pteranodon, however, had long, slender beaks that were totally toothless. They probably ate fish that they caught while skimming over the water. Pteranodon is known from thousands of fossils, most of which are just broken fragments but some of which are complete skeletons. It had a wingspan of at least 26 feet- possibly 33 feet for the largest specimens which made it one of the largest of all flying creatures in the history of Earth. For many decades, it was the largest pterosaur known, but larger ones have since been discovered. (Quetzalcoatlus had a wingspan of 36 feet/lI m, and Ornithocheirus had a wingspan of up to 43 feet/13 m!) Pteranodon flew above the seas of Kansas during the Late Cretaceous. Although it must have come to land to roost and lay its eggs, it does not appear to have lived much on the mainland. Therefore, pictures showing it flying over the heads of tyrant dinosaurs, horned dinosaurs, and/or duckbill dinosaurs are most likely wrong.
Fun Facts[]
Pteranodon is often shown incorrectly with teeth, or with the tail of a Rhamphorhynchus. The Pteranodon briefly seen at the end of The Lost World: Jurassic Park is shown (correctly) with no teeth, but the Pteranodon in Jurassic Park Ill are shown with beakfuls of them (no doubt the result of InGen's genetic manipulations)!
Trivia[]
When Pteranodon was first discovered, it became very famous. While all the pterosaurs found previously were the size of a seagull or smaller, Pteranodon was much bigger than any flying animal today.
Gallery[]
Appearance in other media[]
Jurassic Park[]
- A dozen Pteranodons were seen at the end of The Lost World: Jurassic Park.
- A flock of Pteranodons attack the main characters in Jurassic Park III. Unlike the real animal, they are depicted with teeth.
- Another flock of Pteranodon appear in Jurassic World.
- It is revealed that there are surviving Pteranodon populations on Isla Nublar during Jurassic World: Fallen Kingdom, although they will now face an impending danger, alongside many other creatures, in the form of an erupting volcano. They were seen flying alongside a giant herd running away from Mount Sibo.
- It can be created in the video game Jurassic Park: Builder.
- Pteranodon is in Jurassic World: Evolution via the Return to Jurassic Park DLC.
Read more Pteranodon on Jurassic Park Wiki |
The Land Before Time[]
- One of the main characters of the Land Before Time movies is a young Pteranodon named Petrie.
Read more Pteranodon on Land Before Time Wiki |
We're Back! A Dinosaur's Story[]
- One of the main characters of the movie We're Back! A Dinosaur's Story is a purple female Pteranodon named Elsa. However, she is referred to as a pterodactyl. With a long tail like that of a Rhamphorhynchus.
Links[]
References[]
- https://en.wikipedia.org/wiki/Pteranodon
- https://en.wikipedia.org/wiki/Eutaw_Formation#Ornithodires
- https://twitter.com/Collinson_C/status/1432389038619566083
- ↑ 1.0 1.1 Bennett, S.C. (2000). "Inferring stratigraphic position of fossil vertebrates from the Niobrara Chalk of western Kansas." Current Research in Earth Sciences: Kansas Geological Survey Bulletin, 244(Part 1): 26 pp.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 2.9 Bennett, S.C. (1994). "Taxonomy and systematics of the Late Cretaceous pterosaur Pteranodon (Pterosauria, Pterodactyloida)." Occasional Papers of the Natural History Museum, University of Kansas, 169: 1-70.
- ↑ Carpenter, K. (2003). "Vertebrate Biostratigraphy of the Smoky Hill Chalk (Niobrara Formation) and the Sharon Springs Member (Pierre Shale)." High-Resolution Approaches in Stratigraphic Paleontology, 21: 421-437. DOI: 10.1007/978-1-4020-9053-0
- ↑ 4.0 4.1 Template:Cite book
- ↑ Zimmerman, H., Preiss, B., and Sovak, J. (2001). Beyond the Dinosaurs!: sky dragons, sea monsters, mega-mammals, and other prehistoric beasts, Simon and Schuster. ISBN 0-689-84113-2.
- ↑ Cope, E.D. (1875). "The Vertebrata of the Cretaceous formations of the West." Report, U. S. Geological Survey of the Territories (Hayden), 2: 302 pp., 57 pls.
- ↑ Marsh, O.C. (1876a). "Notice of a new sub-order of Pterosauria." American Journal of Science, Series 3, 11(65): 507-509.
- ↑ Marsh, O.C., (1876b). "Principal characters of American pterodactyls." American Journal of Science, Series 3, 12(72): 479-480.
- ↑ Padian, K. (1983). "A functional analysis of flying and walking in pterosaurs." Paleobiology, 9(3): 218-239.
- ↑ 10.0 10.1 Eaton, G.F. (1910). "Osteology of Pteranodon." Memoirs of the Connecticut Academy of Arts and Sciences, 2:1-38, pls. i-xxxi.
- ↑ 11.0 11.1 11.2 11.3 11.4 11.5 11.6 11.7 11.8 Bennett, S.C. (1992). "Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests." Journal of Vertebrate Paleontology, 12(4): 422-434.
- ↑ von Kripp, D. (1943). "Ein Lebensbild von Pteranodon ingens auf flugtechnischer Grundlage." Nova Acta Leopoldina, N.F., 12(83): 16-32 [in German].
- ↑ Stein, R.S. (1975). "Dynamic analysis of Pteranodon ingens: a reptilian adaptation to flight." Journal of Paleontology, 49: 534-548.
- ↑ 14.0 14.1 Bramwell, C.D. and Whitfield, G.R. (1974). "Biomechanics of Pteranodon." Philosophical Transactions Royal Society B, 267'.
- ↑ Bennett, S.C. (2001). "The osteology and functional morphology of the Late Cretaceous pterosaur Pteranodon. General description of osteology." Palaeontographica, Abteilung A, 260: 1-112.
- ↑ Smith, A.C. (2007). "Pteranodont claw morphology and its implications for aquatic locomotion." Master's Thesis, Michigan State University.