Pteranodons

PTERANODONS

FLYING REPTILES OF THE LATE CRETACEOUS

Updated 06/13/2007

Click HERE to see a Pteranodon sternbergi dig in Western Kansas

Pteranodons 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 during the deposition of the Smoky Hill chalk (wingspreads of 7.5 m (25 ft) or more), and were even larger near the end of the Late Cretaceous.

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 to be discovered consisted of fragments of wing bones but were comparable (though much larger) with pterodactyl remains from the Jurassic of Europe. The only species of pterosaurs that are known to occur in the chalk are the highly developed Pteranodons, including Nyctosaurus.

These flying reptiles do not have teeth or 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 (Wing spread about 20 feet) - Upper Smoky Hill Chalk, Kansas. The wing membranes 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.

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.

Nesting sites are unknown in the fossil record of North America but it likely that they were hundreds of miles from where their abundant remains are found in the Smoky Hill Chalk of modern day Kansas.

Recently, however, a pterosaur egg was found in China with the well-preserved bones of a baby pterosaur inside (See note above).

LEFT: The skeleton of Pteranodon longiceps (lateral view) - Adapted from original drawing by Eaton (1910).

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 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 named two species from the remains, Pterodactylus occidentalis and P. ingens. P. longiceps was named later from a much more complete specimen. 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 remains were probably from the same species, Pteranodon 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

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 found 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 low 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!

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. Found 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.

See Chris Bennett's Pterosaur webpage HERE

See The Pterosaur Database HERE

Downloadable files of Pteranodon Papers 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.

Padian, K. 1983. A functional analysis of flying and walking in pterosaurs. Paleobiology 9(3):218-239.

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.

Credits: The line drawings of Pteranodon sternbergi were adapted from the book, Kansas Geology, Rex Buchanan, Ed., University Press of Kansas, 1984.

Email comments and / or questions to Mike Everhart

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