MartinTate2.jpg (34493 bytes)

Baptornis advenus

Marsh 1877

Toothed marine birds of the Late Cretaceous seas

Copyright 漏 2008-2017 by Mike Everhart

Page created 10/27/2008 - Last updated 03/02/2017

LEFT: An artist's reconstruction of Baptornis advenus, adapted from Martin and Tate (1976, Fig. 20).  Original artist, B. Dalzell (3-1965).   Martin and Tate also noted that the digits of the feet were probably "lobed" and not webbed as shown

Baptornis advenus Marsh 1877

Baptornis (from the Greek, literally meaning "diving bird") is an extinct genus of flightless marine birds from the Late Cretaceous. Although the first hesperornithiform birds (Enaliornis sp.) are known from the latter part of the Early Cretaceous in England, the first known Baptornis remains come from  Santonian age (roughly 85 million years ago) rocks of western Kansas. The type specimen of Baptornis advenus, fragments of a single bone called the tarsometatarsal, were discovered in the Smoky Hill Chalk in Logan County, Kansas by O.C. Marsh鈥檚 collectors, most likely during the 1877 field season. Other, partial specimens are in the collections of the Field Museum of Natural History, and the University of Kansas Museum of Natural History.  One of the best specimens was collected by G.F. Sternberg in the 1930s and acquired by the University of Nebraska State Museum (UNSM 20030 鈥?Shown below).

Somewhat more primitive and about half the size of Hesperornis, the 1 m (~3 ft 4 in) Baptornis had lost the ability to fly (IF it's ancestors had flown?), and possessed only vestigial wings (upper limbs). However, unlike Hesperornis, all of the wing bones were still present, although greatly reduced in size. Baptornis swam with its large legs and feet that had long, widely spaced toes. It is uncertain if the toes of Baptornis were webbed as in Loons and ducks, or lobbed as in modern Grebes and Hesperornis.  The bones of Baptornis were heavy, unlike the light, hollow bones of most flying birds. This helped Baptornis and other hesperornithiforms in diving and swimming underwater by reducing its buoyancy. Although the skull is still unknown, like other hesperornithiforms, Baptornis probably had teeth on its beak to help it catch fish and other prey. The unusually long neck of Baptornis would also have been advantageous in acquiring food. 

Marsh1877-Baptornisa.jpg (22921 bytes) LEFT: In 1877, O.C. Marsh described Baptornis advenus, a new genus and species of hesperornithid on the basis of a "nearly perfect [right] tarso-metatarsal bone," noting that it was distinct enough from Hesperornis to justify a new species. Since then, however, Schufeldt (1915, p.9) noted that the [less than perfect] specimen more likely represents the opposing ends of similar bones from two different individuals, and Martin and Tate (1976) indicated that the Yale Peabody Museum had given a separate number to each portion (YPM 1465 (distal) and YPM 5768 (proximal)). The specimen was collected by G.P Cooper in Gove County on July 4, 1876. It seems highly unlikely that the two pieces came from two different individuals collected on the same day.... when bird bones of any kind are extremely rare in the the Smoky Hill Chalk.

RIGHT: Marsh's figure of the tarsometatarsus of Baptornis advenus was published in 1880. Baptornis was smaller and possibly more primitive than Hesperornis. It also occurs earlier (Santonian) in the Smoky Hill Chalk than does Hesperornis (Campanian).

Marsh1880-193a.jpg (10790 bytes)
"The existence of a small swimming bird contemporary with Hesperornis is indicated by a nearly perfect tarso-metatarsal bone from the same geologic horizon." Marsh (1877, p. 86)

In terms of the number of known specimens, Baptornis advenus is one of the better known birds from the Late Cretaceous after Hesperornis regalis and Ichthyornis dispar. It was first described by O. C. Marsh (1877) as a new genus closely allied with Hesperornis.  It is readily distinguishable from Hesperornis by its smaller size and certain characters of the foot (Martin and Tate, 1976).

LEFT:  Skeletal reconstruction of Baptornis advenus, adapted from Martin and Tate, 1976, Figure 19)

RIGHT: Two views of the right foot of Baptornis advenus (UNSM 20030, adapted from Martin and Tate, 1976, Figure 17).

BaptornisFoota.jpg (9019 bytes)
UNSM20030-Baptornisa.jpg (13511 bytes) LEFT: A fairly complete skeleton of Baptornis advenus (UNSM 20030) collected by G.F. Sternberg and acquired by the University of Nebraska State Museum in 1937. The skeleton includes vertebrae, ribs, uncinate processes, wing bones, half of the pelvis, and most of both rear legs, and feet, as well as preserved intestinal contents (colonites).

In George F. Sternberg's "Field List" for 1936, he described his SP (specimen) 101-36 as: "Bird, Hesperornis regalis. HORIZON: Cretaceous chalk. LOCALITY: About 22 miles southeast of Oakley, northeast 1/2 mile of the Maston? house.  DESCRIPTION: What appears to be the greater part of both feet, vert., limb bone, ribs and other elements. A very small ind. In shale rock. 1- plastered section. All fragments in section."  A handwritten note on the same page  indicates that he later "Opened and prepared" the specimen.. and regarded it as "Choice."

Recent (2008) photographs of the remains are shown below.

UNSM20030-Comparea.jpg (15701 bytes) LEFT: Comparative sizes of the tarsometatarsals, the fibulae and the right femur of the UNSM 20030 Baptornis advenus specimen.

RIGHT: Part of the slab containing ribs and uncinate processes of UNSM 20030. (For more information, see Figs. 7 and 8 of Martin and Tate (1976)

UNSM20030-Ribsa.jpg (24964 bytes)
UNSM20030-RtFemura.jpg (14465 bytes) LEFT: Anterior and posterior views of the right femur of UNSM 20030.

RIGHT: A lateral view (upper) and medial view (lower) of the right half of the pelvis of UNSM 20030. The right and left halves would have been joined by the sacrum.

UNSM20030-RtPelvisa.jpg (26532 bytes)
UNSM20030-Fibiaea.jpg (18107 bytes) LEFT: Anterior and posterior views of both tibiotarsi of UNSM 20030.

RIGHT: Anterior and posterior views of both fibulae of UNSM 20030.

UNSM20030-Tibulaea.jpg (13215 bytes)
UNSM20030-TMTa.jpg (15343 bytes) LEFT: Anterior and posterior views of both tarsometatarsals of UNSM 20030. These bones represent a fusion of the "ankle" bones found in mammals.

RIGHT: Tarsal (toe) bones of UNSM 20030. See the original photo (above) by G.F. Sternberg for the their placement.

UNSM20030-Tarsalsa.jpg (15861 bytes)
UNSM20030Vertebrae2a.jpg (14297 bytes) LEFT: Four vertebrae from of Baptornis advenus (UNSM 20030), mostly in end view.

RIGHT: Vertebrae from of Baptornis advenus (UNSM 20030) in various orientations; from a specimen collected by G.F. Sternberg.

UNSM20030Vertebraea.jpg (21667 bytes)
UNSM20030Colonitea.jpg (15482 bytes) LEFT: "Included with UNSM 20030 are eight coprolites, two of which show small fish jaw and other bones. Most are round or elliptical in cross-section and are elongate, except for the two containing fish material. None shows spiral grooving or surface impressions. George Sternberg, the collector, in a 1937 communication preserved in the records of the University of Nebraska State Museum [UNSM], makes the following reference to the association of these coprolites with Baptornis skeleton:  "There are 7 or 8 coprolites ... 2 show small fish bones. These are small compared to the other coprolites I have seen and were found mingled with the bones." It seems likely that these coprolites are correctly associated with the Baptornis skeleton; if so, they are the only ones known for a Cretaceous bird. However, several of them fit together to for a long rounded structure that might be better interpreted as an intestinal cast. The jaw in one coprolite [RIGHT] was identified by Orville W. Bonner of the University of Kansas (pers. comm., 1972) as Enchodus cf. parvus." (Martin and Tate, 1976, Figure 22)    UNSM20030Colonite-jawa.jpg (19685 bytes)

Baptornis varneri Martin and Cordes-Person, 2007

This new species of Baptornis was described by James Martin and Amanda Cordes-Person from a specimen discovered some years ago by Dan Varner in the Pierre Shale of western South Dakota.

Martin, J. E. and Cordes-Person, A. 2007. A new species of the diving bird Baptornis (Ornithurae: Hesperornithiformes) from the lower Pierre Shale Group (Upper Cretaceous) of southwestern South Dakota. The Geological Society of America, Special Paper 427: 227-237.


"Fossil birds are relatively rare in Cretaceous deposits of the Northern Great Plains, so the discovery of a large, new diving bird was unexpected. From marine deposits of the Niobrara Formation in Kansas small diversity of birds was known, but until now the large diving bird, Hesperornis was the only bird taxon known from the Pierre Shale Group of South Dakota. The new discovery, a partial skeleton of another diving bird, Baptornis, was secured from the Sharon Springs Formation (lower middle Campanian) of the Pierre Shale Group in Fall River County, South Dakota. The specimen is represented by vertebrae, pelvic fragments, and lower leg elements that are similar to but much more robust than Baptornis advenus from the subjacent Niobrara Formation. The new taxon is nearly twice the size of the Niobrara species, principally in robustness rather than in length of elements. Overall, the specimen represents the first occurrence of Baptornis from the Pierre Shale Group, represents a new species, and indicates greater diversity of birds from the Pierre Shale Group than was previously known."

Etymology: Named for Daniel Varner who found the specimen, and for his notable contributions to paleontology in the form of artistic renderings of extinct vertebrates.


American Ornithologists鈥?Union. 1910. Checklist of North American birds; 3rd edition. American Ornithologists鈥?Union, New York, 430 pp.

Anonymous. 1891. Professor [D. W.] Thompson on the systematic position of Hesperornis. Auk 8(3): 304-305.

Baird, D. 1967. Age of fossil birds from the Greensands of New Jersey. Auk 84(2): 260-262

Bell, A. and Everhart, M.J. 2009. A new specimen of Parahesperornis(Aves: Hesperornithiformes) from the Smoky Hill Chalk (Early Campanian) of western Kansas. Kansas Academy of Science, Transactions 112(1/2):7-14.

Brodkorb, P. 1971. Origin and evolution of birds. pp. 19-55 in D. S. Farner and J. R. King (eds.), Avian Biology, Volume 1, Academic Press, New York.

B眉hler, P., L. D. Martin and L. M. Witmer., 1988. Cranial kinesis in the Late Cretaceous birds Hesperornis and Parahesperornis. Auk 105 p. 111-122. (PDF of paper available on-line)

Chinsamy, A., L. D. Martin and P. Dodson. 1998. Bone microstructure of the diving Hesperornis and the volant Ichthyornis from the Niobrara Chalk of western Kansas. Cretaceous Research 19:225-235.

Cracraft, J. Phylogenetic relationships and monophyly of Loons, Grebes, and Hesperornithiform birds, with comments on the early history of birds. Systematic Zoology 31(1): 35-56.

Cumbaa, S. L., C., Schr枚der-Adams, R. G. Day, and A. Phillips. 2006. Cenomanian bonebed faunas from the Northeastern margin, Western Interior Seaway, Canada; pp. 139-155 in S. G. Lucas, and R. M. Sullivan (eds.), Late Cretaceous vertebrates from the Western Interior. New Mexico Museum of Natural History and Science Bulletin 35.

Elzanowski, A. and Brett-Surman, M. K. 1995. Avian premaxilla and tarsometatarsus from uppermost Cretaceous of Montana. Auk 112(3): 762-767.

Everhart, M.J. 2005. Oceans of Kansas - A Natural History of the Western Interior Sea. Indiana University Press, 322 pp.

Everhart, M.J. 2011. Rediscovery of the Hesperornis regalis Marsh 1871 holotype locality indicates an earlier stratigraphic occurrence. Kansas Academy of Science, Transactions 114(1-2):59-68.


Everhart, M.J. and Bell, A. 2009. A hesperornithiform limb bone from the basal Greenhorn Formation (Late Cretaceous; Middle Cenomanian) of north central Kansas. Journal of Vertebrate Paleontology 28(3):952-956.

F眉rbringer, M. 1888. Untersuchungen zur Morphologie und Systematik der V枚gel, zugleich ein Beitrag zur Anatomie der St眉tz 鈥?und Bewegungsorgane; Verlag von Tl.J. Van Holkema, Amsterdam, 1751 p.

Galton, P. M. and Martin, L. D. (2002): Enaliornis, an Early Cretaceous Hesperornithiform bird from England, with comments on other Hesperornithiformes. 317-338. In: Chiappe, L. M. and Witmer, L. M. (eds.): Mesozoic Birds: Above the Heads of Dinosaurs. University of California Press, Berkeley, Los Angeles, London

Gingerich, P. D. 1973. Skull of Hesperornis and early evolution of birds. Nature 243: 70-73.

Gingerich, P. D. 1975. Evolutionary significance of the Mesozoic toothed birds. Smithsonian Contributions to Paleobiology 27: 23-34.

Gregory, J. T. 1951. Convergent evolution: The jaws of Hesperornisand the mosasaurs. Evolution, 5:345-354.

Gregory, J. T. 1952. The jaws of the Cretaceous toothed birds Ichthyornis and Hesperornis. Condor 54(2):73-88, 9 figs., 1 table.

Lane, H. H. 1946. A survey of the fossil vertebrates of Kansas, Part IV, The Birds, Kansas Academy of Science, Transactions 49(4):390-400.

Marsh, O. C. 1872. Discovery of a remarkable fossil bird. American Journal of Science, Series 3, 3(13): 56-57.

Marsh, O. C. 1873. Fossil birds from the Cretaceous of North America. American Journal of Science, Series 3, 5(27):229-231.

Marsh, O. C. 1875. On the Odontornithes, or birds with teeth. American Journal of Science, Series 3, 10(59):403-408, pl. 9-10.

Marsh, O. C. 1876. Notice of new Odontornithes. The American Journal of Science and Arts 11: 509-511.

Marsh, O. C. 1877. Characters of the Odontornithes, with notice of a new allied genus.  American Journal of Science 14:85-87, 1 figure. (Naming and description of Baptornis advenus)

Marsh, O. C. 1880. Odontornithes: A monograph on the extinct toothed birds of North America. U.S. Geol. Expl. 40th Parallel (King), vol. 7, xv + 201 p., 34 pl. (Synopsis of American Cretaceous birds, appendix 191-199)

Marsh, O. C. 1883. Birds with Teeth. 3rd Annual Report of the Secretary of the Interior, 3: 43-88. Government Printing Office, Washington, D.C.

Marsh, O. C. 1893. A new Cretaceous bird allied to Hesperornis. American Journal of Science 45:81-82.

Martin, J. E. 1982. The occurrence of Hesperornis in the late Cretaceous Niobrara Formation of South Dakota. Proceedings of the South Dakota Academy of Science 71(95-97).

Martin, J. E. and Cordes-Person, A. 2007. A new species of the diving bird Baptornis (Ornithurae: Hesperornithiformes) from the lower Pierre Shale Group (Upper Cretaceous) of southwestern South Dakota. The Geological Society of America, Special Paper 427: 227-237.

Martin, J. E. and Varner, D. W. 1992. The highest stratigraphic occurrence of the fossil bird Baptornis. Proceedings of the South Dakota Academy of Science 71:167 (abstract).

Martin, L. D. 1980. Foot-propelled diving birds of the Mesozoic; pp. 1237-1242 in Acta XVII Congress of International Ornithology.

Martin, L. D. 1983. The origin and early radiation of birds. Chapter 9 (pp 291-338) in Bush, A. H. and Clark, G. A., Jr. (eds.), Perspectives in Ornithology. Cambridge University Press, Cambridge.

Martin, L. D. 1984. A new hesperornithid and the relationships of the Mesozoic birds. Kansas Academy of Science, Transactions 87 p. 141-150.

Martin, L. D. and O. Bonner. 1977. An immature specimen of Baptornis advenus from the Cretaceous of Kansas. The Auk 94:787-789.

Martin, L. D. and J. D. Stewart. 1996. Implantation and replacement of bird teeth. Smithsonian Contributions to Paleobiology 89:295-300.

Martin, L. D. and J. Tate, Jr. 1966. A bird with teeth. Museum Notes, University of Nebraska State Museum, 29:1-2.

Martin, L. D. and J. Tate, Jr. 1976. The skeleton of Baptornis advenus (Aves: Hesperornithiformes). Smithsonian Contributions to Paleobiology 27: 35-66.


Mudge, B. F. 1877. Annual Report of the Committee on Geology, for the year ending November 1, 1876. Kansas Academy of Science, Transactions, Ninth Annual Meeting, pp. 4-5. (discovery of Uintacrinus socialisin Kansas, Pteranodon, sharks and birds.)

Rees, J., and J. Lindgren. 2005. Aquatic birds from the upper Cretaceous (Lower Campanian) of Sweden and the biology and distribution of Hesperornithiforms. Palaeontology 48:1321-1329.

Seeley, H. G. 1876. On the British fossil Cretaceous birds. Quarterly Journal of the Geologic Society of London 32: 496-512.

Shufeldt, R. W. 1915. The fossil remains of a species of Hesperornis found in Montana. Auk 32(3): 290-284.

Shufeldt, R.W. 1915. Fossil Birds in the Marsh Collection of Yale University. Transactions of the Connecticut Academy of Arts and Sciences 19: 1-110, 15 pl.

Snow, F. H. 1887. On the Discovery of a Fossil Bird Track in the Dakota Sandstone. Kansas Academy of Science, Transactions 10:3-6

Sternberg, C. H. 1917. Hunting Dinosaurs in the Badlands of the Red Deer River, Alberta, Canada. Published by the author, San Diego, Calif., 261 pp.

Tokaryk, T. T., S. L. Cumbaa, and J. E. Storer.  1997.  Early Late Cretaceous birds from Saskatchewan, Canada: the oldest diverse avifauna known from North America.  Journal of Vertebrate Paleontology, 17:172-176.

Townsend, C. W. 1909. The use of the wings and feet by diving birds. Auk 26(3): 234-248.

Walker, M. V. 1967. Revival of interest in the toothed birds of Kansas. Kansas Academy of Science, Transactions 70(1):60-66.

Williston, S. W. 1898. Birds. The University Geological Survey of Kansas, Part 2, 4:43-53, pls.5-8.

Williston, S. W. 1898. Bird tracks from the Dakota Cretaceous. The University Geological Survey of Kansas, Part II, 4:50-53, Fig. 2. (Re-publication of photograph originally published by Snow, 1887)