PTERANODONS FLYING REPTILES OF THE LATE CRETACEOUS  copyright © 2000-2008 by Mike Everhart Updated 05/24/2008

Pterosaurs were flying reptiles. They were superbly adapted for flight, with hollow, air-filled bones, a relatively large, birdlike brain (Seeley, 1871; Wellnhofer, 1991), and membranous wings that were supported by the elongated fourth finger of each hand. Their upper bodies were stiffened by rigidly binding the fused dorsal vertebrae, ribs, and sternum together into a solid structure that supported the large muscles needed to power their wings. Some smaller pterosaurs were apparently covered with “fur-like” bristles and it is likely that they were "warm-blooded" to some extent.  Besides the elongated “wing-finger,” they had three clawed fingers on each hand, and four clawed toes on each foot. The smallest (Pterodactylus) was about the size of an American robin, and one of the largest (Quetzalcoatlus) had a wingspread as large as a light airplane (11-12 m/ 36-39 ft.).

Pteranodons ("wing without tooth") were a group of Late Cretaceous flying reptiles that were characteristically toothless and tail-less (they did have short tails).  They grew to large size (wingspreads of 7.5 m (25 ft) or more) during the deposition of the Smoky Hill Chalk (87-82 mya), and were even larger near the end of the Late Cretaceous.  The largest species (P. longiceps) found in Kansas had a wingspread of about 8 m (26 ft.) but would probably have weighed no more than 11 kg (25 lb.). Compared to their heads and their wings, their bodies are almost absurdly small. One comparison provided by Hankin and Watson (1914) was that "with a body little larger than that of a cat, they had a span of wing asserted in some cases to have reached 21 feet or more!" LEFT: The skeleton of Pteranodon longiceps (lateral view) - Adapted from original drawing by Eaton (1910). CLICK FOR LARGER VERSION

During the summer and fall of 1870, O. C. Marsh and his Yale scientific expedition collected fossils from as far west as Wyoming and Utah. Late in November, they made a brief visit to western Kansas in the vicinity of Fort Wallace where he was assigned a military escort. The weather was cold but they were still able to collect for several days along the Smoky Hill River in what are now Wallace and Logan counties. In a short note published after returning to Yale in mid-December, Marsh (1871) noted only that "some interesting reptilian and fish remains" were collected during their two-week stay in Kansas

In his first mention of a North American pterosaur, Marsh (1871) reported that the distal ends of two long bones (two metacarpals from the wings of two individuals (YPM 1160 and 1161) had been found, and noted that they were not unlike those from Europe figured by Richard Owen in 1851. Marsh (1871, p. 472) also noted that the bones were thin-walled and hollow. From these few fragments, he named a new species Pterodactylus Oweni, "in honor of Professor Richard Owen of London." Marsh estimated the size of the creature from the fragments and noted that the outstretched wings would have measured "not less than twenty feet!"

Surprisingly, and as a complete fabrication since no skull material was reported to be present, Marsh also indicated that "the teeth are smooth, and compressed." In his much more complete description of additional remains of this and two other species collected by the 1871 expedition, Marsh (1872, p. 244) again noted the presence of teeth in Pteranodon: "The teeth found with remains of this species, and supposed to belong to them, are very similar to the teeth of Pterodactyls from the Cretaceous of England. They are smooth, compressed, elliptical in transverse outline, pointed at the apex and somewhat curved." Of the teeth of a second species (Pterodactylus ingens), Marsh wrote (ibid., p. 247) that "the dental characters of this species are at present only known from a single crown of a tooth; found with one series of the specimens and from two larger and very perfect teeth found by themselves, which agree so closely with the former that they deserve notice in this connection. These specimens are less curved and less compressed than the teeth referred to Pt. occidentalis, but in other respects they are nearly identical."  According to Chris Bennett (pers.comm. 2003), the teeth collected by Marsh in association with his initial Pteranodon wing bones were fish teeth, probably those of an Ichthyodectes.

Marsh, however, apparently assumed that his American "Pterodactyle" would have teeth like its European cousins and was hedging his bet on their discovery when the first skull was found. In that regard, he was not the only one who would be playing "fast and loose" with this conclusion. His rival E. D. Cope (1872, p. 337) also indicated, slightly more conservatively, that Pteranodon skulls "were slender and the teeth indicated carnivorous habits." As shown in an illustration in a book called Buffalo Land (Webb, 1872), it is clear that Cope believed that at least one of the species he had named (Ornithochirus umbrosus) had teeth.

In the summer of 1871, Marsh and the second Yale scientific expedition returned to Kansas. Marsh was able to return to the spot where he had found the first remains of a Pteranodon, and he located additional pieces of the same bone. By the time Marsh (1872) published more complete descriptions, however, the giant Pteranodons were already taking a back seat to the recent discovery of toothed birds in western Kansas. Marsh noted that the name he gave to the first specimen (Pterodactylus Oweni) was preoccupied by a specimen described by Seeley and replaced it with the name Pterodactylus occidentalis. Besides this species, Marsh (1872, p. 246-247) collected several specimens of "the most gigantic of Pterosaurs," which he called P. ingens (YPM 1160 and 1172) and estimated had a wingspread "of nearly 22 feet!" Marsh also named another, smaller species (P. velox; YPM 1176) found in 1871 on the basis of what he believed were differences he saw in the wing bones.

Bennett (1994) examined the Marsh collection at the Yale Peabody Museum and indicated that because of the stratigraphic level in which the pterosaur remains collected by Marsh in 1871 and 1872 occurred, they were all probably Pteranodon longiceps. In that regard, Bennett (1994, p. 14) considered all the early names given by Marsh and Cope to be nomen dubia because the material does not exhibit any species-specific characters and was too fragmentary to be accurately identified beyond the genus Pteranodon.

Cope apparently found at least two sets of Pteranodon remains during his trip to Kansas in late 1871. In a short note, Cope (1872a, p. 337) named two species, Ornithochirus umbrosus (AMNH 1571) and O. harpyia (AMNH 1572), that were apparently distinguished from one another only on the basis of size. In doing so, he accepted Seeley's name for the genus and apparently ignored Marsh's Pterodactylus without further comment. In a narrative that preceded the listing of the two new species, Cope (ibid., p. 323) described them in their natural habitat: "The flying saurians are pretty well known from the descriptions of European authors. Our Mesozoic periods had been thought to have lacked these singular forms until Professor Marsh and the writer discovered remains of species in the Kansas chalk. Though these are not numerous, their size was formidable. One of them, Ornithochirus harpyia Cope, spread eighteen feet between the tips of its wings, while the O. umbrosus, Cope, covered nearly twenty-five feet with his expanse. These strange creatures flapped their leathery wings over the waves, and often plunging, seized many an unsuspecting fish; or, soaring, at a safe distance, viewed the sports and combats of the more powerful saurians of the sea. At night-fall, we may imagine them trooping to the shore, and suspending themselves to the cliffs by the claw-bearing fingers of their wing-limbs."

While this image of pteranodons hanging from rocks along the seashore has been shown in numerous recreations over the years, it is probably just a fantasy. As noted by Stein (1975), it would have been impossible for Pteranodon to land on all fours on level ground without collapsing the wings first and thus losing lift. Performing such a landing against the vertical wall of a cliff would seem to be a death-defying act. Furthermore, none of the cores of the wing claws I have collected or examined show any damage on the tips as might be expected from a daily routine of hanging from one's fingertips.

The first Pteranodon specimens found in North America were discovered in the Smoky Hill Chalk of western Kansas by O.C. Marsh in 1870.  The remains he collected consisted only of fragments of wing bones.  However, they were readily comparable (though much larger) with pterodactyl remains from the Jurassic of Europe. The only pterosaurs that are known to occur in the Smoky Hill Chalk are the highly developed pteranodons, including P. longiceps,  P. sternbergi, and Nyctosaurus.

These flying reptiles do not have teeth or long tails like the earlier pterosaurs found in the Jurassic of Europe, and are generally much larger. LEFT: An old version of the skeleton of Pteranodon longiceps (wingspread about 20 feet) - Upper Smoky Hill Chalk, Kansas. The wing membranes were narrower and are no longer considered to have been connected to the lower legs.

They were apparently "warm blooded" in some respects, and may have had a thin covering of hair on their bodies. Pteranodons fed primarily on fish and squid. Their role in the Late Cretaceous Inland Sea was probably similar to modern sea birds such as the albatross and pelican, and they may have spent most of their lives soaring over the ocean looking for food. We are not sure how they fed but it is unlikely that they were "skimmers," that is, taking fish from the surface while in flight.

PTERANODON NEWS - A recent discovery (Wang and Zhou, 2004) in China of an Early Cretaceous (Aptian, ~ 121 mya) pterosaur embryo preserved inside an egg in China appears to have answered the question of whether or not they laid eggs. The 53mm by 41 mm egg contained a nearly ready to hatch embryo that would have had a wingspread of about 27 cm (11 in.). While the question of egg laying in the much larger Pteranodon is still open to question, it seems likely that they would have reproduced in a similar fashion.  

LEFT: Another version of Eaton's 1910 drawing of Pteranodon longiceps. In this case, the figure is an illustration from: Hankin, E. H. and D. M. S. Watson. 1914. On the flight of Pterodactyls. The Aeronautical Journal, 18: 324-335. Note the small size of the Pteranodon's body compared to the length of the head, and to the wings. Pteranodons were superbly adapted to flight, including their hollow, pneumatic bones and the way in which their dorsal vertebrae were fused together with the ribs to form a solid structure that supported the flight muscles. While they were excellent long distance flyers, they probably spent more time soaring than flapping their wings.

Pteranodon longiceps 

Pteranodons were first discovered in the upper chalk of Logan County, Kansas by O. C. Marsh in 1870. The only remains found were fragments of wing bones, but they were recognizable as being similar to the pterodactyls found in Europe.  Marsh initially named two species from the remains, Pterodactylus occidentalis and P. ingens. P. longiceps was named later from a much more complete specimen. Cope also named two species from specimens that he collected in 1871, and both men contended that these giant flying reptiles also had teeth. It wasn't until about 1876 that the first skulls were found and it was discovered that these flying reptiles did NOT have teeth and the name was changed to Pteranodon. It was later noted by Bennett (1994) that all of the early specimens were probably from the same species, P. longiceps.

LEFT: The skull of Pteranodon longiceps (lateral view, about 4 feet) (Adapted from the O. C. Marsh drawing of the skull of YPM-1177)

These two drawings were adapted from Lucas, F. A. 1929. Animals of the Past. American Museum of Natural History, Handbook No. 4, New York. LEFT: A comparison between the sizes and the skeletons of an adult Pteranodon longiceps and a California Condor - Gymnogyps californianus.   The wing spread of the Pteranodon is about 24 feet, while that of the Condor is about 10 feet. RIGHT: The different bone structures of wings in bats, pterodactyls, a primitive bird (Archæopteryx) and a modern bird.

Pteranodon sternbergi

Click HERE to see a Pteranodon sternbergi dig in Western Kansas

A large pterosaur, with a wing spread of more than 20 feet which is characterized by a large, upward pointing crest. P. sternbergi is found fairly commonly in the lower chalk. The skull of the type specimen was collected by G. F. Sternberg in 1952 in Graham County, KS. Fossilized pterosaur remains are extremely fragile, but sometimes include wing and toe claws. Pteranodon remains first occur in the lower chalk near Hattin's marker unit 5. P. longiceps is a related species that occurs higher in the chalk. The males of this species have long, slender crest that extends almost as far behind the skull as the jaw extends to the front! Females typically do not have a large crest.

LEFT: The type specimen (FHSM VP-339) of Pteranodon sternbergi in the Sternberg Museum of Natural History. RIGHT: A life sized model of P. sternbergi, also in the Sternberg Museum.

LEFT: Wing fingers and claws from a nearly complete but headless specimen of Pteranodon sp. (FHSM VP-2062) in the Sternberg Museum of Natural History.  The specimen was found by George F. Sternberg in September, 1956, northwest of WaKeeney, in Trego County. Without the skull, we cannot determine whether this specimen represents P. sternbergi or P. longiceps since the post-cranial material is non-diagnostic between these two species (Bennett, 1992). RIGHT: Detail of wing claws.

LEFT: Three views of the skull of a juvenile Pteranodon sternbergi (CMC VP7203) found by Pam Everhart and donated to the Cincinnati Museum Center where it is currently on display.

LEFT: A nearly complete (lacking the humerus) left wing of a Pteranodon collected by G. F. Sternberg and exhibited in the Fick Fossil and History Museum in Oakley, Kansas. RIGHT: Detail of the same wing showing the three digits of the hand and the cores of the wing claws.

LEFT: Here are some pics of the lower leg bones of a Pteranodon that I collected several year ago (identified by Chris Bennett)

LEFT: One of the first drawings of a complete Pteranodon leg and hip.

LEFT/RIGHT: Lower leg and foot of Pteranodon longiceps (Sternberg Museum of Natural History)

CLICK HERE to see a Pteranodon sternbergi dig in Western Kansas

Nyctosaurus gracilis

Nyctosaurus was a smaller pterosaur that occurs from the middle of the chalk upwards.  It was first described by O. C. Marsh in 1876. Other than size, the skeleton differs from P. longiceps most noticeably in the shape of the humerus (upper wing bone), and in the lack of a crest on the skull.

LEFT: The type specimen of Nyctosaurus bonneri (FHSM VP-2148) at the Sternberg Museum. Bennett (1994) considered N. bonneri to be a junior synonym of N. gracilis.

	LEFT and RIGHT: The first nearly complete specimen of Nyctosaurus gracilis at the Field Museum of Natural History in Chicago, IL. FM25026 was described by Williston (1902). Found by H. T. Martin in western Kansas. (Photographed in 2003)
	LEFT: The skull and lower jaw of Nyctosaurus gracilis (FM25026). This was one of the first pteranodon skulls ever to be photographed for publication (Williston, 1902). RIGHT: The skeleton of FM25026, with labels.

LEFT: A drawing of the skeleton of Nyctosaurus gracilis from Williston's "Osteology of Reptiles" (1925, p. 299, fig. 190). Until recently, Nyctosaurus was not known to have crests like the larger species of Pteranodon (see below).

LEFT: The nearly complete specimen of a Nytosaurus gracilis from the Smoky Hill Chalk of western Kansas on exhibit in the University of Nebraska State Museum, Lincoln Nebraska.  Collected and prepared by Greg Brown (UNSM).

The recent discovery in the Smoky Hill Chalk of western Kansas of two specimens of Nyctosaurus with very large crests is discussed in a paper by Chris Bennett: Bennett, S. C. 2003. New crested specimens of the Late Cretaceous pterosaur Nyctosaurus. Paleontologist Zeitschrift, 77:61-75. (See photographs of the actual specimens here: Chris Bennett web page) LEFT: A cast of the reconstructed skull of one of the Nyctosaurus specimens found and prepared by Kenneth Jenkins from the Smoky Hill Chalk (cast also by Kenneth Jenkins).  Note that this version of the KJ1 specimen was reconstructed to move the lower jaw upward in articulation, and to remove non-cranial bones. The extremely large crest on these small flying reptiles raises questions about what it was used for and how they were able to fly.

"Skimming Nyctosaurs" painting © 2003 by John Conway.   Used with permission of John Conway. (Click on picture to enlarge)

See Chris Bennett's Pterosaur webpage HERE

See The Pterosaur Database HERE

Downloadable files of Pteranodon Papers HERE

Pterosaur Site (Jurassic pterosaurs) HERE

Further reading:

Anonymous. 1872. On two new Ornithosaurians from Kansas. American Journal of Science, Series 3, 3(17):374-375. (Probably by  O. C. Marsh)

Bennett, S. C. 1987. New evidence on the tail of the pterosaur Pteranodon (Archosauria: Pterosauria). pp. 18-23 In Currie, P. J. and E. H. Koster (eds.), Fourth Symposium on Mesozoic Terrestrial Ecosystems, Short Papers. Occasional Papers of the Tyrrell Museum of Paleontology, #3.

Bennett, S. C. 1990. Inferring stratigraphic position of fossil vertebrates from the Niobrara Chalk of western Kansas. pp. 43-72, In Bennett, S. C. (ed.), Niobrara Chalk Excursion Guidebook, The University of Kansas Museum of Natural History and the Kansas Geological Survey.

Bennett, S. C. 1992. Sexual dimorphism of Pteranodon and other pterosaurs, with comments on cranial crests. Journal of Vertebrate Paleontology 12 p. 422-434.

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.

Bennett, S. C. 2000. New information on the skeletons of Nyctosaurus. Journal of Vertebrate Paleontology 20(Supplement to Number 3): 29A. (Abstract)

Bennett, S. C.  2003. New crested specimens of the Late Cretaceous pterosaur Nyctosaurus. Paläontologische Zeitschrift, 77:61-75.

Betts, C. W. 1871. The Yale College Expedition of 1870. Harper’s New Monthly Magazine, 43(257):663-671. (Issue of October, 1871)

Bonner, O. W. 1964. An osteological study of Nyctosaurus and Trinacromerum with a description of a new species of Nyctosaurus. Unpub. Masters Thesis, Fort Hays State University, 63 pages.

Brower, J. C. 1983. The aerodynamics of Pteranodon and Nyctosaurus, two large pterosaurs from the Upper Cretaceous of Kansas. Journal of Vertebrate Paleontology 3(2):84-124.

Cope, E. D. 1872a. On the geology and paleontology of the Cretaceous strata of Kansas. Annual Report of the U. S. Geological Survey of the Territories 5:318-349 (Report for 1871).

Cope, E. D. 1872b. On two new Ornithosaurians from Kansas. Proceedings of the American Philosophical Society 12(88):420-422.

Cope, E. D. 1874. Review of the Vertebrata of the Cretaceous period found west of the Mississippi River. U. S. Geological Survey of the Territories Bulletin 1(2):3-48.

Cope, E. D. 1875. The Vertebrata of the Cretaceous formations of the West. Report, U. S. Geological Survey of the Territories (Hayden). 2:302 p, 57 pls.

Eaton, G. F. 1903. The characters of Pteranodon. American Journal of Science, ser. 4, 16(91):82-86, pl. 6-7.

Eaton, G. F. 1904. The characters of Pteranodon (second paper). American Journal of Science, ser. 4, 17(100):318-320, pl. 19-20.

Eaton, G. F. 1908.  The skull of Pteranodon.  Science (n. s.) XXVII 254-255.

Eaton, G. F. 1910.  Osteology of Pteranodon.  Memoirs of the Connecticut Academy of Arts and Sciences, 2:1-38, pls. i-xxxi.

Harksen, J. C. 1966. Pteranodon sternbergi, a new fossil pterodactyl from the Niobrara Cretaceous of Kansas. Proceedings South Dakota Academy of  Science 45:74-77.

Lane, H. H. 1946. A survey of the fossil vertebrates of Kansas, Part III, The Reptiles, Kansas Academy Science, Transactions 49(3):289-332, figs. 1-7.

Marsh, O. C. 1871. Scientific expedition to the Rocky Mountains. American Journal of Science ser. 3, 1(6):142-143.

Marsh, O. C. 1871.  Notice of some new fossil reptiles from the Cretaceous and Tertiary formations.  American Journal of Science, Series 3, 1(6):447-459.

Marsh, O. C. 1871. Note on a new and gigantic species of Pterodactyle.  American Journal of Science, Series 3, 1(6):472.

Marsh, O. C. 1872. Discovery of additional remains of Pterosauria, with descriptions of two new species. American Journal of Science, Series 3, 3(16) :241-248.

Marsh, O. C. 1876. Notice of a new sub-order of Pterosauria. American Journal of Science, Series 3, 11(65):507-509. 

Marsh, O. C., 1876. Principal characters of American pterodactyls. American Journal of Science, Series 3, 12(72):479-480.

Marsh, O. C. 1881.  Note on American pterodactyls.  American Journal of  Science, Series 3, 21(124):342-343.

Marsh, Othniel Charles. 1882.  The wings of Pterodactyles. American Journal of Science, Series 3, 23(136):251-256, pl. III.

Marsh, O. C. 1884.  Principal characters of American Cretaceous pterodactyls. Part I. The skull of Pteranodon.  American Journal of Science, Series 3, 27(161):422-426, pl. 15.

Miller, H. W. 1971. The taxonomy of the Pteranodon species from Kansas. Kansas Academy of Science, Transactions 74(1):1-19.

Miller, H. W. 1971. A skull of Pteranodon (Longicepia) longiceps Marsh associated with wing and body parts. Kansas Academy of Science, Transactions 74(10):20-33. 

Russell, D. A. 1988. A check list of North American marine cretaceous vertebrates Including fresh water fishes, Occasional Paper of the Tyrrell Museum of Palaeontology, (4):57.

Schultze, H.-P., L. Hunt, J. Chorn and A. M. Neuner, 1985. Type and figured specimens of fossil vertebrates in the collection of the University of Kansas Museum of Natural History, Part II. Fossil Amphibians and Reptiles. Miscellaneous Publications of the University of Kansas Museum of Natural History 77:66 pp.

Seeley, Harry G. 1871.  Additional evidence of the structure of the head in ornithosaurs from the Cambridge Upper Greensand; being a supplement to "The Ornithosauria." The Annals and Magazine of Natural History, Series 4, 7:20-36, pls. 2-3. (Discovery of toothless pterosaurs in England)

Shor, E. N. 1971. Fossils and flies; The life of a compleat scientist - Samuel Wendell Williston, 1851-1918, University of Oklahoma Press, 285 pp.

Sternberg, C. H. 1990.  The life of a fossil hunter, Indiana University Press, 286 pp. (Originally published in 1909 by Henry Holt and Company)

Sternberg, G. F. and M. V. Walker. 1958. Observation of articulated limb bones of a recently discovered Pteranodon in the Niobrara Cretaceous of Kansas. Kansas Academy of Science, Transactions, 61(1):81-85.

Stewart, J. D. 1990. Niobrara Formation vertebrate stratigraphy, pages 19-30, In Bennett, S. C. (ed.), Niobrara Chalk Excursion Guidebook, The University of Kansas Museum of Natural History and the Kansas Geological Survey. 

Wang, X. and Z. Zhou. 2004. Pterosaur embryo from the Early Cretaceous. Nature 429:621. 

Wellnhofer, P. 1991. The illustrated encyclopedia of pterosaurs. Crescent Books, New York, 192 pp.

Williston, S. W. 1891. The skull and hind extremity of Pteranodon. American Naturalist 25(300):1124-1126.

Williston, S. W. 1892. Kansas pterodactyls. Part I. Kansas University Quarterly 1:1-13, pl. i.

Williston, S. W. 1893. Kansas pterodactyls. Part II. Kansas University Quarterly 2:79-81, with 1 fig.

Williston, S. W. 1895. Note on the mandible of Ornithostoma. Kansas University Quarterly 4:61.

Williston, S. W. 1896. On the skull of Ornithostoma. Kansas University Quarterly 4(4):195-197, with pl. i.

Williston, S. W. 1897. Restoration of Ornithostoma (Pteranodon). Kansas University Quarterly 6:35-51, with pl. ii.

Williston, S. W. 1902. On the skeleton of Nyctodactylus, with restoration. American Journal of Anatomy. 1:297-305.

Williston, S. W. 1902. On the skull of Nyctodactylus, an Upper Cretaceous pterodactyl. Journal of Geology, 10:520-531, 2 pls.

Williston, S. W. 1902. Winged reptiles. Pop. Science Monthly 60:314-322, 2 figs.

Williston, S. W. 1903. On the osteology of Nyctosaurus (Nyctodactylus), with notes on American pterosaurs. Field Mus. Publ. (Geological Ser.) 2(3):125-163, 2 figs., pls. XL-XLIV.

Williston, S. W., 1904.  The fingers of pterodactyls. Geology Magazine, Series 5, 1(2): 5:59-60.

Williston, S. W. 1911 The wing-finger of pterodactyls, with restoration of Nyctosaurus. Journal of Geology. 19:696–705.

Williston, S. W. 1912. A review of G. B. Eaton's "Osteology of Pteranodon". Journal of Geology. 20:288.

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