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Hesperornis regalis Marsh 1872

Marine birds with teeth in the Late Cretaceous seas


Copyright © 2000-2014 by Mike Everhart

Last updated 01/19/2014



Detail of a painting by Ely Kish, Copyright © Ely Kish; used with permission of Ely Kish (EMAIL) - Click HERE for the entire painting.

Hesperornis (pronounced HES-per-OR-nis) means "western bird."  Professor O. C. Marsh reportedly found the first remains of a bird (Hesperornis regalis) in the Smoky Hill Chalk of "Trego County" on July 25, 1871 [This locality is suspect - almost all specimens that were collected by the Yale Scientific Expedition in late July came from Logan County, some 40 miles to the west].  The specimen (YPM 1200) was did not include a skull and Marsh had no way of knowing the full significance of his discovery. Marsh (1872a) wrote, "One of the treasures secured during our explorations this year [1871] was the greater portion of the skeleton of a large fossil bird, at least five feet in height, which I was fortunate enough to discover in the Upper Cretaceous of Western Kansas. This interesting specimen, although a true bird --- as clearly as shown by the vertebræ and some other parts of the skeleton -- differs widely from any known recent or extinct forms of that class, and affords a fine example of a comprehensive type. The bones are all well preserved. The femur is very short, but the other portions of the legs are quite elongated. The metatarsal bones appear to have been separated. On my return, I shall fully describe this unique fossil under the name Hesperornis regalis."

Actually, Marsh had found a foot bone of Hesperornis about a year earlier but didn't realize it. 

Williston (1898) noted that "late in the season of 1870, Professor Marsh, with an escort of United States soldiers, spent a short time on the upper part of the Smoky Hill River collecting vertebrate fossils. The material then collected served for the description of a number of interesting types by Marsh. It included the first known specimen of 'Odontornithes,' a foot bone brought in with other material, but which was not discovered in the material until after other specimens had been obtained later. In June of the following year Marsh again visited the same region, with a larger party and a stronger escort of United States troops, and was rewarded by the discovery of the skeleton which forms the type of Hesperornis regalis Marsh, together with other material."

In a later article, Marsh (1872b) noted that the "most interesting bird with teeth yet discovered is perhaps Hesperornis regalis, a gigantic diver, also from the Cretaceous of Kansas, and discovered by the writer in 1870." Marsh neglected to mention that the original discovery did not include a skull or teeth, but adds that "a nearly perfect skeleton was obtained in Western Kansas by Mr. T. H. Russell and the writer in November, 1872." The reader is left to assume that this specimen of Hesperornis (YPM 1206) was the first one discovered with teeth. The skull was illustrated in Marsh's 1880 monograph on Odontornithes (Plate I).

LEFT: A photograph of the 1872 Yale College Scientific Expedition: O.C. Marsh is standing in the center of the back row. T.H. Russell is sit on the left end of the front row. A larger version of the 1872 expedition is HERE.  

Note that T.H. Russell went on to become a well respected medical doctor and was Marsh's personal physician at the time of Marsh's death in 1899.

LEFT: A mount of swimming Hesperornis regalis in the Yale Peabody Museum, based on the YPM 1206 skeleton discovered in 1872 by T.H. Russell.

RIGHT: A Late Cretaceous scene illustrated by Zdenĕk Burian showing a Hesperornis resting on a beach along the Western Interior Seaway, along with a pair of Ichthyornis. (Adapted from Prehistoric Animals by J. Augusta and Z. Burian)

Marsh, O. C. 1880. Odontornithes: A monograph on the extinct toothed birds of North America. Report of the Geological Exploration of the Fortieth Parallel (King), volume 7, xv + 201 p., 34 pl.

     The first Bird fossil discovered in this region was the lower end of the tibia of Hesperornis [YPM 1205], found by the writer in December, 1870, near the Smoky Hill River in Western Kansas. Specimens belonging to another genus of Odontornithes were discovered on the same expedition. The extreme cold, and danger from hostile Indians, rendered a careful exploration at the time impossible.

In June of the following year, the writer again visited the same region with a larger party, and a stronger escort of United States troops, and was rewarded by the discovery of the skeleton which forms the type of Hesperornis regalis Marsh. Various other remains of Odontornithes were secured, and have since been described by the writer. Although the fossils obtained during two months of exploration were important, the results of this trip did no equal our expectations, owing in part to the extreme heat (110o to 120o Fahrenheit, in the shade) which, causing sunstroke and fever, weakened and discouraged guides and explorers alike.

     A considerable part of these Cretaceous deposits still remained unexplored, and in the autumn of 1872, a third expedition through this territory was undertaken by the writer, with a small party. Additional specimens of much interest were secured, including the type of the genus Apatornis, and one nearly complete skeleton of Hesperornis, -- an ample reward for the hardship and danger we incurred.

In the Appendix of that same publication (pages 195-196), Marsh provides additional details on the locality of the early specimens: 

     “The type specimen of Hesperornis regalis (number 1200) was found by the writer, in July, 1871. The locality was on the south bank of the Smoky Hill River, about twenty miles east of Fort Wallace. This fossil was imbedded in the gray calcareous sha1e, nearly in the same horizon us the one first found. The skull was wanting, but many other parts of the skeleton, including the vertebrae and the bones of the legs und feet, were well preserved. Portions of five other individuals were found by the writer on the same expedition.
     The most perfect specimen of this species yet discovered (number 1206) was obtained by Mr. T.H. Russell and the writer in October, 1872. This skeleton was nearly complete when found, the skull, lower jaws, and pelvis being especially well preserved. The locality was near that of the type specimen. Another important skeleton (number 1207) was found in July, 1875, by Prof. B. F. Mudge, who was then in charge of one of the writer's exploring parties.” 

See Everhart (2011) for additional information regarding the discovery and the revised age of the type specimen of Hesperornis regalis Marsh.

Class: Aves

Subclass: Hesperonithes

Order: Hesperornithiformes

Family: Hesperornithidae

Genus: Hesperornis Marsh, 1872

Hesperornithids were large flightless birds that swam in the oceans of the late Cretaceous and preyed on small fish.   The lower jaw (dentary) and the back portion of the upper jaw (maxilla) of Hesperornis had many sharp teeth. Hesperornis fossils are rare, and are found only in the upper portions (Campanian age) of the Smoky Hill Chalk. The remains of these birds are more common in Cretaceous deposits to the north of Kansas where the weather was probably cooler. It is likely that they were much like modern penguins, living in colonies where they raised their young, and feeding at sea. They were also apparently limited to the Northern Hemisphere, much as modern penguins are limited to the Southern Hemisphere. HESPER5A.jpg (19548 bytes)
LEFT: A model of Hesperornis regalis in the Natural History Museum at the University of Kansas. The restoration was done by by Melvin Douglas under the direction of H. H. Lane (see Lane, 1947, p. 393).

RIGHT: A close-up of the head of the Hesperornis model.  Note the absence of teeth on the premaxilla. A recent paper by Hieronymus and Witmer (2010) suggests that the tooth-bearing bones of Hesperornis (and Ichthyornis) would not have been covered with a horny (keratinous) sheath; rather the maxillae and the dentaries would have been covered with skin and scales or feathers. Only the non-tooth bearing portions of the jaws (premaxillae and predentary) would have been covered with a keratinous sheath (see modified photo)

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sm-hespa.jpg (7696 bytes) LEFT: Diving Hesperornis shown as a detail in the underwater diorama painting at the Sternberg Museum of Natural History

RIGHT: Two hesperornithids are shown here in a detail from a mural by Charles Bonner in the Keystone Gallery.

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marhesa.jpg (17484 bytes) LEFT: The restored skeleton of Hesperornis regalis Marsh (about 1/6 life size). Adapted from  Plate VI, The University Survey of Kansas, Volume IV, Paleontology, Part I, Upper Cretaceous, Samuel W. Williston, Paleontologist, Kansas State Printer, 1898. Williston used Marsh's reconstruction of Hesperornis for this figure (The bird would have been about three feet in height in this pose).

RIGHT: Bones of the scapular arch of Hesperornis as figured and described by O.C. Marsh in 1877:

“The scapula is long and slender, and has no acromial process. The clavicles are separate, but meet on the median line, as in some very young existing birds. The coracoids are short, and much expanded where they join the sternum. The latter has no distinct manubrium, and is entirely without a keel. The wings were represented by the humerus only, which is long and slender, and without any trace of articulation at its distal end. Its position was close to the ribs, and it was probably nearly or quite concealed beneath the integuments, as in Apteryx. This rendered the rudimentary wings of no possible service in flight or swimming.”

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According to Williston (1898), "Hesperornis regalis, the best known species of the genus, was a bird measuring about 6 feet from the point of the bill to the tip of the feet when outstretched, or standing about 3 feet high.  It was an aquatic bird, covered with soft feathers, wholly wingless, the rudimentary wing bones doubtless being enclosed under the skin, and not at all effective in locomotion. The legs were strong and moderately long; the neck was long and flexible. The bill was long, and was provided with small but effective conical teeth set in the jaw firmly. Those of the upper jaw were few in number and set in the back part, while those of the mandibles formed a complete series.  The jaws were united in front by cartilage only, permitting considerable mobility, which was doubtless very serviceable in swallowing their prey, which must have consisted of fishes caught by diving. The bones of the body were solid throughout, not hollow, as in almost all living birds. The sternum had no keel, as in the flying birds, and those descended from flying birds, but was as in the ostrich.  The vertebræ and skeleton, aside from the teeth, are not unlike those of modern birds, and, were the skull yet unknown, would be unhesitatingly referred to the subclass to which the ostrich, cassowary, and rhea belong." 
UNSM-Hesp-La.jpg (30389 bytes) LEFT: A model of the skull of Hesperornis regalis in left lateral view in the collections of the University of Nebraska State Museum (DORSAL VIEW - VENTRAL VIEW). This cast  was part of an earlier exhibit about Hesperornis and is probably based on a skull at the Yale Peabody Museum.  The model of the complete bird in the exhibit was a composite of two fairly complete Hesperornis specimens acquired from G.F. Sternberg (one in 1936; see below).
LEFT: Drawing of the skull of Hesperornis regalis in left lateral view  (adapted from Gingerich 1973, fig. 1). Note that there were no teeth in the premaxilla. 
vp2069t.jpg (9166 bytes) LEFT: One of the more complete skeletons of Hesperornis regalis (FHSM VP-2069; minus a skull) is in an exhibit at the Sternberg Museum of Natural History in Hays, Kansas. It is mounted in a 3-D, left lateral view, and exhibits many of the unusual characters of this group of toothed, swimming birds (Hesperornithiformes). 

The pictures below show details of the mounted, partial specimen.

vp2069ja.jpg (30056 bytes) LEFT: FHSM VP-2069 - Front limb and rib cage

RIGHT: FHSM VP-2069 - Reconstruction of the sternum (light areas are actual bone), with coracoids.  Larger view of coracoids is HERE.

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vp2069ba.jpg (25439 bytes) LEFT: FHSM VP-2069 - Rear upper limb bones, left lateral view

RIGHT: FHSM VP-2069 - Left rear foot.  Hesperornids had broad, individual toes,  not webbed feet.

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VP22293Ca.jpg (26814 bytes) LEFT: FHSM VP-2293 - Right scapula (above) and right humerus (below).
VP22293Ba.jpg (31082 bytes) LEFT: FHSM VP-2293 - Two views of the right humerus - Note that the wing (upper limb) in Hesperornis was very reduced in size and probably non-functional.
VP22293Aa.jpg (17346 bytes) LEFT: FHSM VP-2293 - A series of dorsal vertebrae and the proximal ends of two double-headed ribs.
FHSM VP-186a.jpg (21199 bytes) LEFT: Right and left lateral views of the posterior dorsal vertebrae and pelvis of Hesperornis regalis (FHSM VP-189) discovered by Dr. L.D. Wooster of Fort Hays State University near Monument Rocks in Gove County in 1948 while on a fossil hunting trip with George F. Sternberg

RIGHT: The pelvis of Hesperornis regalis in left lateral and dorsal view as figured by O.C. Marsh (1880, Plate X).

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LEFT - Plate I from Marsh's 1880 monograph on Odontornithes showing five views of the skull and lower jaw of Hesperornis regalis Marsh. The figure was drawn by Frederick Berger based on the YPM 1206 specimen discovered by T.H Russell near Russell Springs, Kansas in 1872, and collected by the Yale College Scientific Expedition. The lithographic engraving was done by Emile Crisand and is life-sized as published. The skull is 251 mm in length (just a little under 10 inches). Scan of the original Plate I provided by Dr. Jane Davidson.

RIGHT:  The skull of Hesperornis regalis in left lateral, posterior, ventral and dorsal views. Teeth are shown at fig. 2. (adapted from Heilmann, G. 1926. The Origin of Birds. London)

LEFT:Upper and side views of the lower jaw of Hesperornis regalis Marsh, cervical vertebrae, and tooth (From Williston, 1898, originally figured in Marsh, 1880).

LEFT: The headless skeleton of Hesperornis regalis (AMNH FR 5100) discovered by the elder Sternberg's son,  Charles M. Sternberg, in 1907 in the Smoky Hill Chalk near Twin Butte Creek, Logan County, Kansas; now in the collection of the American Museum of Natural History. 

"Unfortunately, the skull is missing, otherwise the nearly complete specimen is present, and strange to say in normal position. ...  Strange indeed was this long-necked diver with its tarsus at right angles with the body and its powerful web-footed feet. The body was narrow, a little over four inches wide, with a backbone like the keel of a boat. The head was ten inches long and armed with sharp teeth." (Sternberg, 1917, p. 265-266) (Note that the large, shield-like sternum and the ribs are also missing.

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LEFT: The partial remains of a Hesperornis regalis (UNSM 1212) collected by George F. Sternberg and sold to the University of Nebraska State Museum in 1936. (Adapted from a photo by G.F. Sternberg - SP 107-31).  

Sternberg's notes said:
4-19-5-36 Hesperornis regalis (toothed bird)
Horizon: Niobrara Cretaceous, blue shale
Locality: About five miles southeast of Russell Springs, Kansas. Logan Co.
Discovered by Mrs. M.V. Walker.
"The following bones are present in this specimen: fifteen vertebrae (cervical and dorsal); one femur, one patella, one post-pubis, one tarso-metatarsal, three toes, three ribs with unicate process, and other fragments which are not on exhibition. Remarks: This great flightless bird which had teeth, reached a length of nearly six feet. Its wings were rudimentary and of no use in either air or water, but the great feet were webbed. They were used to paddle in the sea with an outward lateral instead of a downward stroke. Few skeletons, which are anything like complete, have been found of this bird. All are from western Kansas."

UNSM-Hesp01a.jpg (29310 bytes) LEFT: The reconstructed pelvis of Hesperornis regalis (UNSM 1212) in left lateral view

RIGHT: The femurs of UNSM 1212 in posterior view

UNSM-Hesp02a.jpg (12922 bytes)
UNSM-Hesp03a.jpg (17819 bytes) LEFT: The reconstructed tibotarsi of UNSM 1212 in posterior view

RIGHT: The tarsometatarsi of UNSM 1212 in anterior view.

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hesperca.jpg (32169 bytes)  LEFT: Hesperornis feeding on a school of Enchodus. Copyright 2001 © Carl Buell; used with permission of Carl Buell.


The Geology Museum at the University of Wisconsin - Madison has collected a significant number of specimens from the Smoky Hill Chalk in Kansas, including the partial remains of a Hesperornis. These photos of their Hesperornis reconstruction were provided by Christopher Ott:

Body 1; Body 2; Skull 1; Skull 2

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usnmhesa.jpg (21904 bytes) LEFT: A skeletal reconstruction of Hesperornis regalis in the ancient seas exhibit of the Smithsonian Institution (USNM), Washington, D.C.
LEFT: A mural depicting a colony of Hesperornis on the shore of the Western Interior Sea. (University of Kansas Museum of Natural History, Lawrence, Kansas)

Baptornis advenus Marsh 1877

Marsh1880-192a.jpg (25362 bytes) LEFT: In 1877, O.C. Marsh described Baptornis advenus, a new genus and species of hesperornithid (repeated in his 1880 monograph at left), on the basis of a "nearly perfect tarso-metatarsal bone," noting that it was distinct enough from Hesperornis to justify a new species. Since then, however, Schufeldt (1915b) noted that the 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)).

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).

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"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 best 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)

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 legs, as well as preserved intestinal contents (colonites).

Recent (2008) photographs of the remains are shown on the Baptornis web page.

fickhesa.jpg (27579 bytes) LEFT: A small exhibit of hesperornithid bones in the Fick Fossil and History Museum, Oakley, Kansas, many of which are probably from the same specimen. Collected and donated by Vi and Earnest Fick.  Bone at the upper left is a humerus. As noted by Martin and Tate (1976). this exhibit may also include some bones of Baptornis advenus.

RIGHT: A copy of Figure 20 from Martin and Tate (1976) showing three Baptornis feeding on small fish. The sketch is on display in the exhibit at the Fick Fossil and History Museum in Oakley, Kansas.

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Parahesperornis alexi Martin 1984

hespskia.jpg (11923 bytes) RIGHT: PLATE VIII.--- Photograph of scutes and feather impressions of the tarsal region of Hesperornis specimen (KUVP 2287) published Williston in the University Geological Survey of Kansas. Enlarged.

S. W. Williston (1898)  wrote "A specimen now in the University Museum, collected by Mr. H. T. Martin recently [1894, Graham County], is remarkable in showing the scuta of the tarso-metatarsal region, together with the feathers. A photographic reproduction of this part of the specimen is shown in Plate VIII. I have sketched in the tarso-metatarsal bone, to show it's position. Indications of feathers are also seen on the back portion of the head, and everywhere they appear to be more plumulaceous than the ordinary type of feathers." (Williston, S. W., 1898. Birds. The University Geological Survey of Kansas, Part 2, 4:43-53, pls.5-8.)  See also Williston, 1898, On the dermal covering of Hesperornis.

NOTE: KUVP 2287 was re-described by Larry Martin (1984) as the type specimen of a new genus and species of hesperornithid bird, Parahesperornis alexi.
             Martin, L.D. 1984. A new hesperornithid and the relationships of the Mesozoic birds. Kansas Academy of Science, Transactions 87:141-150.

KUVP2287-Pelvisa.jpg (28108 bytes) LEFT: The pelvis of the type of Parahesperornis alexi (KUVP 2287) in left lateral view.

RIGHT: The femurs and tibiotarsi of KUVP 2287

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Bussen2008-1da.jpg (20876 bytes) LEFT: The right tarsometatarsus of Parahesperornis sp. (FHSM VP-17312) collected by Pete Bussen in the upper Smoky Hill Chalk (MU 22) of western Logan County. This lower limb bone is about 9.7 cm in length and came from a medium-sized swimming bird about the size of a modern cormorant.

RIGHT: Proximal and distal end views of the same specimen. The proximal end appears to have a possible pathology that has destroyed the bone surface in the center of the joint.

See: 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.

Bussen2008-1Ja.jpg (19731 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.

A very early Enaliornis-like bird from North America (The oldest bird remains in the United States)

Enaliornis (Seeley, 1876) is a genus of hesperornithine birds from the Early Cretaceous Cambridge Greensand of England. Two species have been described: Enaliornis barretti and E. sedgwicki.  Although remains are fragmentary and incomplete, this is currently the oldest known hesperornithine. In June, 1979, two fragments of a Enaliornis-like tarsometatarsus were surface collected from the basal Lincoln Limestone Member of the Greenhorn Limestone in western Russell County, Kansas. The limb bone would have come from a swimming bird somewhat smaller than Hesperornis or Baptornis. The specimen was mentioned by Martin (1983) and Tokaryk, et al. (1997) but was never fully described or figured. The English Enaliornis material was re-described more recently by Galton and Martin (2002).

See:   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.

FHSM VP-6318Aa.jpg (17214 bytes) LEFT: Two views of the proximal and distal ends of the right tarsometatarsus (FHSM VP-6318) of an Enaliornis-like bird from the basal Greenhorn Limestone (Middle Cenomanian) of Kansas. This specimen represents the oldest bird bone in Kansas and the United States, and is almost as old as the material  described from the Carrot River area in Saskatchewan, Canada by Tokaryk, et al., 1997, which is currently the oldest bird fauna in North America. Their specimens also included an Enaliornis-like bird. (Everhart and Bell, 2009)

RIGHT: Four views of the distal end of the specimen. The tarsometatarsus is a bone in the lower leg of birds. It is formed from the fusion of several bones homologous to the ankle (tarsal) and foot (metatarsal) of mammals. (See skeletal drawing of a Hesperornis leg HERE)

FHSM VP-6318Ba.jpg (28756 bytes)


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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.

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