April 4, 2022 Scott Kraus

Pteranodon Wasn’t a Dinosaur at All

Pteranodon, pronounced “ter-AN-o-DON”, was a flying carnivorous reptile that lived during the Late Cretaceous period about 75-85 million years ago. Its name means “Winged and Toothless”, referring to its toothless beak, which was like that of modern birds, and its huge wingspan, which was much larger than any modern day bird. Pteranodon was in the genus of Pterosaurs, which are often incorrectly referred to as dinosaurs, but dinosaurs technically belong to the groups Saurischia and Ornithischia, not Pterosauria. Pterosaurs were the earliest known vertebrates to have developed the ability to fly. Of all the pterosaurs, Pteronodons have the distinction of having the most fossil specimens found, all of which have been unearthed in North America.

Quick Facts

What did Pteranodon look like?

Pteranodon was most distinctive for the massive wingspan and large crest of the males. The length of the wingspan was as large as 23 feet across. The crest was long and extended backward and upward from the skull. It was almost as long as its beak, which contained no teeth, like modern birds. The beaks were long, thin and pointed at the end. The upper jaw was longer than the lower jaw and curved upward. The smaller Pteranodons found to date would have been either female or juvenile males that hadn’t reached their full size or developed the large crest. The smaller crest was more triangular in shape. Weight estimates of Pteranodon have varied considerably, although it probably didn’t have very bulky musculature since it spent a lot of time in the air. It is also worth noting that its tail was relatively short.

Physical attributes of Pteranodon

As its name suggests, the Pteranodon, meaning “winged” and “toothless” had a beak containing no teeth, unlike  earlier pterosaurs like Pterodactlylus.  The beak of Pteranodon was slender and in all probability very sharp for use in feeding.  The Pteranodon had a distinct bite as well, as the protruding upper jaw and upward curve gave the ancient reptile a unique profile. Also distinctive are the cranial crests rising at the back of the head.  Consisting of three bones extended from the base of the spinal Columbus to right above the eyes, the crest was probably a display feature, and varied in size and tilt within different subspecies.  In almost all cases, the Pteranodon displays sexual dimorphism, in which the size and proportions of the animals are altered by gender.  In this case, the males had larger bodies and also larger crests. The average wingspan of an adult male Pteranodon was 18 feet, or 5.6 meters. They were about 1 and a half times larger than the females, which had wingspans of about 12 feet, or 3.8 meters, long.

What did Pteranodon Eat?

Although Pteranodon had no teeth, it was a carnivore. Paleontologists know that Pteranodon ate meat because its fossils were found in rocks formed in marine environments, which indicated that it flew a lot over the ocean in search of fish much like a seabird of today would do. Fossilized fish bones have been found in the stomach of one Pteranodon and in between the jaws of another. This flying reptile may have scooped the fish out of the water then ate them whole, like a pelican. It may also have fished like a diving bird, as one paleontologist pointed out: the Pteranodon is built like modern diving birds. In addition to fish, this Pterosauria could also have scavenged for invertebrates, like bugs or mollusks.

How Did Pteranodon Move?

Paleontologists obviously know that Pteranodon flew, but the question of whether it was bipedal or quadrupedal when standing or walking has long been under debate. However, experts on the Pterosaur genus mostly agree that the flying reptiles were quadrupedal, or used four legs to stand and walk. This indicates that they would have used their wings and wing digits as forelimbs.”  Researchers have discovered Pterosaur trackways that have indicated as much. In addition to flying, researchers have discussed the possibility that the ancient reptile may also have been able to swim.

The Flight of Pteranodon

Paleontologists can often infer about primitive, extinct animal behavior from similarities between the fossil record and observations of modern animals. So even though Pteranodon is much larger than modern birds, scientists have noticed the high aspect ratio for its wing to chord length is comparable to an albatross, a modern-day above average sized seabird. The high aspect ratio, of the wingspan to chord length, results in a relatively long and skinny wing and consequently lower drag. What that means for Pteranodon is an ability to glide and soar over long distances, like albatrosses. Although studies have indicated that Pteranodon relied on more flapping than modern seabirds. Pteranodon took off into the air from standing on its four limbs, using mainly the strength of their forelimbs to power into flight.

Male and Female Pteranodons

There are two main size variations in Pteranodons that were once thought to be indications of different species, but are now known to represent males and females of the same species. The male is about one and a half times bigger than the female, with a large crest that points upward and backward. Small Pteranodon fossils have been found twice as often as the larger ones, some of those are female and some are juvenile males. Both females and juveniles have smaller crests, but the females have differently structured pelvic bones. The female pelvic bones are relatively large and wide-set, indicating a spacious birth canal for producing eggs. Since immature males have similar skulls to females, paleontologists have only been able to establish gender of the remains for fossils with pelvic bones intact and present. Male Pteranodons developed larger crests upon reaching sexual maturity and becoming fully grown.

What was the Purpose of the Crest?

The Pteranodon’s crest would have been very distinctive in the male of the species, but paleontologists haven’t completely agreed on the function of the crest in general. The first interpretation of the crest’s purpose was in 1910 by George Francis Eaton. He proposed an aerodynamic counterbalance and a muscle attachment point. The problem with his theories, as pointed out later, is they didn’t take into account the varying sizes of crests among the species. Another theory, proposed by a later paleontologist was that it worked as a rudder. Other paleontologists liked the idea, but again, it didn’t take into account the smaller crests, just the large male crest. The best hypothesis seems to be the most obvious, that the males had larger crests for mating purposes in terms of sexual attraction and individual identification. This accounts for the large crest among fully grown Pteranodons and it explains why females and juvenile males would only have a small crest.

The Discovery of Pteranodon

The first Pteranodon fossils were found in 1870, by Othniel Charles Marsh, in the Smoky Hill Chalk deposits of western Kansas. The chalk beds were once at the bottom of the Western Interior Seaway, which was a large sea over the middle section of North America. The first fossil specimens were partial wing bones and a tooth from the Xiphactinus, a primitive fish which the paleontologist mistakenly attributed to the new flying reptile. In 1871, Marsh first named the fossil Pterodactlyus Oweni, which was a much smaller genus from Europe that was well known at the time. In 1876, after a dispute with a rival paleontologist who had also found Pteranodon fossils which he also misattributed, Marsh realized it was a new species and he called it Pteranodon.

The Importance of Pteranodon

Pteranodon was the first Pterosaur to be discovered outside of Europe. It also has the most fossil samples of any member of the Pterosaur family. Paleontologists have records of about 1,200 specimens and many of them are in good shape with almost whole and articulated skeletons. Pteranodon is also unique in the popular misconception that it was a dinosaur, although it was a reptile and relative of dinosaurs, nevertheless, it is still an interesting creature. Pteranodon has one of the largest wingspans of any known flying creature and it played a significant role in the ecosystem of the Western Interior Seaway.