Field Guide, Part 2; Sharks and Bony Fish

VERTEBRATES: Animals having a spinal column, including fish, reptiles and birds. Fossils are generally limited to skeletal remains but sometimes also include calcified cartilage, scales and stomach contents. (My list of fish references is here)

You can now download a copy of this early article on Kansas Sharks by Williston - Provided by the Kansas Geological Survey.

Cartilaginous fish, including sharks: Sharks are an old family of fish, dating back many millions of years to the Devonian Period. They were common predators and scavengers in the Western Interior Sea. For picture of the teeth of more species, click here for Sharks of Kansas

"Ginsu" sharks grew lengths of 20 feet or more, and were one of the top predators in the Western Interior Sea. They were probably very similar in behavior to the modern Great White Shark, but were not closely related. Their razor sharp, triangular, blade-like teeth are the largest shark teeth found in the chalk and their large, disk shaped vertebrae are also found occasionally. Sometimes the entire shark including skin is preserved as a fossil. Charles Sternberg found a very large Cretoxyrhina in the late 1800s. On page 113-114 of C. H. Sternberg's "Life of a Fossil Hunter," he describes the discovery of a 20 [foot?] shark (Cretoxyrhina) from the chalk (probably Gove Co., south of Park, KS). The specimen was nearly complete, with "over 250 teeth"....

Quoting Sternberg, "This is the first time and, I believe, the only time that so complete a specimen of this ancient shark has been discovered. The
column and other solid parts were composed of cartilaginous matter which usually decays so easily that is rarely petrified. I suppose my specimen was old at the time of its death, and bony matter had been deposited in the cartilage. It is not very likely that such a specimen will ever be
duplicated. Dr. Eastman's [1895?] study of this skeleton enabled him to make synonyms of many species which had been named from teeth alone."

According to Sternberg, "the most complete skeleton of the Cretaceous shark, Oxyrhina mantelli [Oxyrhina = Cretoxyrhina] Agassiz ever discovered in any formation" was sold to the "Ludwig-Maximilian University of Munich." Apparently, the study he was referring to is: Eastman, C. R., 1895. Bietrage Kenntniss Gattung Oxyrhina mit besonderer Berucksichtigung von Oxyrhina mantelli Agassiz. Palaeontographica 41:149-192.

For some reason, this species seems to reach it's largest size and greatest abundance in the lower one third of the chalk (Late Coniacian), and then, judging from the size of the shed teeth that are found, becomes rarer and smaller in the upper chalk. Cretoxyrhina then became extinct worldwide by the middle of the Campanian (82 mya).

The sharks of the genus Squalicorax (also called the Crow Shark, from Corvus corax = the genus/species of modern ravens) were medium in size, and tended to become larger toward the end of the Cretaceous. Like Cretoxyrhina, however, the genus Squalicorax also became extinct, in this case during early Maastrichtian time.

In 1992, I was also fortunate enough to discover the front half of a 2 meter Squalicorax falcatus (below). The specimen (CMC VP 5722) was donated to the Cincinnati Museum Center.

Shimada, K. and Cicimurri, D.J. 2005. Skeletal anatomy of the Late Cretaceous shark, Squalicorax (Neoselachii: Anacoracidae). Paläontologische Zeitschrift 79(2): 241-261.

Class Osteichthyes (Bony Fish):

Bony fish (including teleosts) were evolving rapidly at this time and beginning to produce the variety of modern shapes and sizes that we see today. Some of the largest bony fish that ever swam were in the Western Interior Sea during the Cretaceous Period and have left abundant remains. Many times, however, only the tail of the fish remains as evidence of the leftovers from a larger predator's meal.

Most of the remains that are found were from relatively large fish that must have been high in the food chain. None of the smaller fish, which must have existed in great abundance to support the other fish, mosasaurs, plesiosaurs, Pteranodons and Hesperornids are well represented in the fossil record either because their skeletons were too small to be preserved except under special conditions, and more likely, they were usually consumed by larger predators.

Subclass Actinopterygii

Division Halecostomi

Suborder Pycnodontidae

Micropycnodon kansasensis

Pycnodontids: Small fishes, similar in many respects to the modern Parrot Fish, with crushing teeth that look like small round pegs.

LEFT: Apparently, this fish "nibbled" on the invertebrates that were attached to inoceramid shells at the bottom of the ocean, although they are more commonly found and may have preferred much shallower water near shore. Pycnodontids are found from the Early Cretaceous Kiowa Shale (Albian) through the lower half of the Smoky Hill Chalk (Coniacian).

RIGHT: A well preserved and fairly complete specimen of Micropycnodon kansasensis (KUVP 7030) in the collection of the University of Kansas.

LEFT: A photograph of two pycnodont jaw plates. The one at far left was found by Shawn Hamm; the other was found by Pam Everhart in 1991. Two additional pictures of the right, lower jaw of the 1991-84 pycnodontid (Micropycnodon) are here: (Photo 1; Photo 2)

LEFT: A left prearticular toothplate of a juvenile pycnodont collected by Keith Ewell in 2004 from Trego County. The white color of some of the teeth indicates oxidation of the enamel due to weathering. (Scale = mm)

LEFT: A nearly complete specimen of Micropycnodon kansasensis (KUVP 127042) in the collection of the University of Kansas Museum of Natural History found by Laverne "Duffer" Mauck in southeastern Gove County in 1994 near Hattin's Marker Unit 4. Head is to the left.

RIGHT: A close up of the spiky scales covering ventral side (keel) of this fish. The spines are made up of a enamel like substance called ganoin which covers the scales and dermal bones of ganoid fish (Also visible on the type and KUVP 7030)

Division Ginglymodi

Lepisosteus sp. (Gars)

Gar fish - A single, disarticulated specimen (KUVP 36243) was reported by Wiley and Stewart (1977) from the lower chalk (Late Coniacian, zone of Protosphyraena perniciosa) of Trego County, KS.

LEFT: FHSM VP-5114 -These large Lepisosteus sp. scales were collected from the Kiowa Formation of Kiowa County and are Albian in age. Scales of Lepisosteus sp. are also known from the Buildex Quarry in McPherson County, along with the teeth of Lepidotes sp.

RIGHT: Three teeth from the Lepisosteus sp. (KUVP 36243) remains described from Trego County by Wiley and Stewart (1977).

Division ?

Family Pachycormidae ?

Genus Protosphyraena Leidy, 1857

Protosphyraena:

A large, fairly common fish that would have looked somewhat like a modern swordfish with a sword-like beak and long, sickle shaped fins. They grew to large size. The pectoral fins and shoulder bones are most frequently preserved as fossils of this genus, and in several species the fins have a distinct saw toothed, leading edge. The genus includes: Protosphyraena perniciosa (Cope, 1874); Protosphyraena nitida (Cope, 1872); Protosphyraena tenuis Loomis, 1900; Protosphyraena gladius (Cope, 1873), and Protosphyraena bentonianum (Stewart, 1898).

LEFT: This is the most recent concept of what Protosphyraena may have looked like, based on the first recovery of a nearly complete specimen. Although lacking the anterior portion of the skull, it is the most complete specimen of Protosphyraena ever found, and provides valuable information regarding the characteristics of this fish. The fish is rather short for the size of it's long, saw-toothed pectoral fins and large nearly vertical caudal fin. The pelvic fins are long and streamer-like, and emerge just behind the pectoral fins.

RIGHT: The tail of a Protosphyraena sp. specimen (KUVP 49419) in the University of Kansas collection. Closer view HERE

The skull, with a sharp rostrum (nose) is also found preserved in the chalk and is readily recognized by the flat, blade-like teeth. The anterior teeth in both jaws point forward. The remaining skeleton was made up of poorly ossified bone and has not been found preserved, except for the hypural bone of the caudal fin.

RIGHT: The sharp snout of a Protosphyraena nitida skull (from Hay, 1903). These relatively heavy pieces of bone are fairly common in the chalk. The heavy scapulo-coracoid and pectoral fins are usually found preserved separately.

Protosphyraena perniciosa (Cope, 1874)

A large predatory fish with long pectoral fins that had a sharp, serrated leading edge. Fins and elements of the pectoral girdle are found most often. Found in lower 1/3 and extreme upper portions of the chalk.

LEFT: A complete set of Protosphyraena perniciosa fins (FHSM VP-80) that are on exhibit in the Sternberg Museum, Hays, Kansas. These were collected in the lower Smoky Hill chalk of Ellis County by George F. Sternberg. Each fin measures over 36 inches, and the complete mount measures 77 inches with the scapulo-coracoid bones. (CLICK TO ENLARGE)

The original name given to this fish by Cope in 1874 was Ichthyodectes perniciosus. He did not recognize that it was in the genus Protosphyraena, named by Leidy in 1857.

LEFT: A complete skull of Protosphyraena sp. (FHSM VP-81) Probably P. perniciosa) that is on exhibit in the Sternberg Museum, Hays, Kansas. This specimen was collected and prepared by George F. Sternberg, and measures 15 inches from the base of the skull to the tip of the rostrum. Note the forward facing teeth in both the upper and lower jaws.

Protosphyraena nitida (Cope, 1872)

LEFT: Originally called Erisichthe nitida by Cope in 1873, Protosphyraena nitida was a medium sized predatory fish with pectoral fins characterized by fine lines perpendicular to the leading edge of the fin. Found in lower 1/3 of chalk. Mike and Pam Everhart collected the only known complete skull and fins of this fish. The specimen (LACM 129752) is now at the Los Angeles County Museum of Natural History.

	LEFT: (EPC 1994-04) Protosphyraena nitida fins do not have the jagged, saw-toothed edges found in P. perniciosa. Instead they have fine grooves at right angles to the edge of the fin (CLICK HERE FOR CLOSE-UP).
	LEFT: An associated partial skull and pectoral fin of a very small (about 3 ft or 1 m) Protosphyraena nitida (EPC 2003-14) that I collected in the lower chalk of southeastern Gove County (2003). This specimen is unusual both for the small size and the association of a rostrum with a pectoral fin. The specimen shows evidence of being scavenged by a shark, probably Squalicorax falcatus.

Protosphyraena tenuis (Loomis, 1900)

A medium sized predatory fish with sickle shaped fins characterized by a moderately serrated leading edge. The serrations are not thickened in cross section as they are in P. perniciosa. This species appears to replace P. perniciosa above the lower 1/3 of the chalk.

	*LEFT: A partial pectoral fin of Protosphyraena tenuis* Loomis 1900 in my collection (EPC 1994-15). CLICK HERE FOR A DETAIL OF THE EDGE OF THIS FIN.**
	*LEFT: A partial pectoral fin of Protosphyraena tenuis* Loomis 1900 in my collection (EPC 1995-38). CLICK HERE FOR A DETAIL OF THE EDGE OF THIS FIN.**

Protosphyraena gladius (Cope, 1873)

LEFT: A very large but relatively rare fish that is found in the upper 2/3 of the chalk. Pectoral fins are massive in both length and thickness. This fish was recently determined not to a Protosphyraena (swordfish). Little was known about the skull until recently, but now it appears to be a large filter feeder like Leedsichthys from the Jurassic of England. It will soon be redescribed and renamed. Protosphyraena gigas (Stewart, 1999) is a junior synonym of P. gladius.

Protosphyraena bentonianum (Stewart, 1898)

This species is a poorly known from the Lincoln Limestone Member of the Greenhorn Limestone (Upper Cenomanian) that was described from a single specimen collected in Mitchell County by S. W. Williston in 1897. More recently Keith Ewell and I have collected Protosphyraena teeth from below the contact of the Dakota Sandstone and Graneros Shale in Russell County.

LEFT: Albin Stewart (1898, p. 27) described a new species of Protosphyraena from the Lincoln Member (Upper Cenomanian) of the Greenhorn Limestone that had been found by S. W. Williston in 1893 in southern Mitchell County. Stewart named the new species Protosphyraena bentonianum.The specimen (KUVP 414) consists of a 20 cm (8 in) rostrum and several unidentifiable bone fragments. Although the type material does not contain teeth, it is likely that the teeth in the photo at above left are also from P. bentonianum. The inset is a close-up of the surface texture of the snout which Stewart believed to be distinctive for the species. However, the same texture also appears on Protosphyraena snouts from the Smoky Hill Chalk.

Note that the species name was first published as "bentonia" in 1898 by Stewart, but then was noted to be a typographical error by Stewart (1900).

LEFT: A recently collected (2005) specimen of Protosphyraena perniciosa(?) / P. bentonianum from the Fort Hays Limestone of Jewell County (private collection). Note the same surface texture on the snout as noted above.

Subdivision Teleostei (teleost fish)

Order Ichthyodectiformes

Family Ichthyodectidae

Ichthyodectids:

A family of medium to very large, primitive bony fish; includes Gillicus, Ichthyodectes and Xiphactinus.

LEFT: All ichthyodectid fishes were covered with oval-shaped scales that were wider than they were long. Sometimes these scales are preserved in the chalk, unassociated with other vertebrate remains. The scale at left measures about 3.5 cm (1.5 in.) by 2 cm (the anterior part of the scale is in the lower part of the picture). From the large size of this scale, it is most likely from a Xiphactinus or an Ichthyodectes.

Xiphactinus audax:

Xiphactinus was the largest bony fish of the Late Cretaceous, reaching lengths of nearly 20 feet. These fish must have been the terror of the seas as far as anything smaller was concerned. Nicknamed the "Bulldog" fish because of the upward thrust of it's lower jaw, the fish would have been able to swallow very large prey, and this sometimes got them into trouble.

RIGHT: Xiphactinus audax and Gillicus

A number of complete specimens of Xiphactinus have been found with smaller fish (Gillicus) inside. This could indicate that death was somehow caused by the smaller fish but we will probably never know. The specimen shown above (FHSM VP-333 and VP-334) is in the Sternberg Museum at Fort Hays State University and was collected by George F. Sternberg in 1952. Click on the picture to see larger image. Xiphactinus page HERE.

While the name Xiphactinus has been around since 1870, there has been considerable confusion over which name is actually correct: Xiphactinus audax (Leidy, 1870) or Portheus molossus (Cope, 1872). Joseph Leidy named the fish from a fragment of a pectoral fin (USNM 52; at left) which was donated to the Smithsonian by Dr. George M. Sternberg a year before E. D. Cope gave the name of Portheus molossus to a collection of several nearly complete specimens found near Fort Wallace. Leidy won by virtue of being first to publish, but Cope's name was more popular and is still in use in many collections of Cretaceous fish

The lower jaw of Xiphactinus audax (about 10 inches in length). The teeth of this fish are very large and are generally unequal in size.

The vertebrae of Xiphactinus audax. These are the largest bony fish vertebrae found in the Smoky Hill chalk and may reach 3 or more inches in diameter. The vertebrae are spool-like, without ornamentation. This fish has no living relatives in today's ocean but would probably have looked much like a modern tarpon.

**Pictures of two Xiphactinus audax vertebrae are HERE and HERE (scale - mm)**

The pectoral fins of Xiphactinus were large and heavy, and were almost entirely made of solid bone.

Ichthyodectes ctenodon:

A larger ichthyodectid fish with heavy jaws and small, equally sized teeth (see jaws below). It grew to lengths of 8 to 10 feet and was a predator on smaller fish. The complete specimen (below) is a juvenile and is one of the smallest examples known of this species. Note that the bone on top of the head is the supraoccipital and was where major muscles were attached.. it is NOT at horn or spike and would not be visible in the living fish. It is possible that this is a composite specimen and the skull is too small.

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FHSM VP-760

About 49 inches long

(Click here for skull)

Vertebrae are large, spool shaped, and without ornamentation. Ichthyodectes is very similar to Gillicus in shape, but somewhat larger.

LEFT: The skull of Ichthyodectes ctenodon in the Museum of Natural History at The University of Kansas.

The lower jaw of Ichthyodectes ctenodon showing the uniform size of the teeth.

Gillicus arcuatus

A medium-sized, very elongate predatory fish with thin, blade like jaws having only a single row of very tiny teeth. These fish reached a length of 5 or 6 feet and may have fed on plankton or other small food material filtered from the water around them, but more likely ate smaller fish. Their remains are fairly common. The genus was named by O. P. Hay (1898) in honor of Dr. Theodore Gill of the National Museum (USNM - Smithsonian). It had originally been described in 1875 and named Ichthyodectes arcuatus by E. D. Cope.

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Gillicus arcuatus

FHSM VP-420

1.3 m

One of the best known examples of this fish is found inside the body cavity of a much larger Xiphactinus audax that is on exhibit at the Sternberg Museum. (Click here for a view of a complete Gillicus in the Denver Museum of Nature and Science)

Although these fish are sometimes considered to be 'toothless'... and "even filter-feeders", a close look at their jaws will show that they are well-armed with many small teeth. A six foot long fish with a big mouth is quite capable of taking smaller fish and squid, with or without an array of impressive teeth.

These three Gillicus skulls were prepared by Chuck Bonner and are on exhibit in the Keystone Gallery, 25 miles south of Oakley, in Logan County, Kansas.

Subfamily Saurodontinae:

Saurocephalids (Saurodon leanus Hays, Saurocephalus lanciformis Harlan and Prosaurodon pygmaeus Loomis) - A medium sized predatory fish with a sword-like projection from the lower jaw (pre-dentary). Teeth are small, equal-sized and blade shaped.

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LEFT: Painting of Saurodon leanus by Charles Bonner, Keystone Gallery

RIGHT: The skull of Saurodon leanus, showing the unusual extension of the lower jaw (predentary).

The type specimen of Saurocephalus lanciformis Harlan 1824 is the only surviving fossil from the Lewis and Clark Expedition of 1803-4. It was found in NW Iowa and is now in the Academy of Natural Sciences of Philadelphia (ANSP 5516)

See also this historical paper: Harlan, R., 1824. On a new fossil genus of the order Enalio sauri, (of Conybeare). Journal of the Academy of Natural Sciences of Philadelphia, Series 1, 3(pt. 2):331-337; pl. 12, figs. 1-5.

	*LEFT: The skull of Saurodon leanus* Hays in the exhibits of the Sternberg Museum of Natural History. (FHSM VP-168)**
	LEFT: The lower jaws / predentary, and partial right upper jaw / premaxilla of Saurodon leanus from the Fryxell Geology Museum at Augustana College in Rockford, Illinois. This specimen was collected by George Sternberg from the Smoky Hill chalk and acquired by the college.

Order Tselfatiiformes

Family Plethodidae

Plethodids:

The plethodids are a fairly common but relatively primitive group of fish that had skeletons composed of varying amounts of cartilage. In most cases only a small portion of the skull of the fish is preserved. The Family Plethodidae includes the genera: Niobrara, Zanclites, Luxilites, Syntegmodus, Bananogmius, Pentanogmius ("Anogmius" evolutus), Martinichthys, Thryptodus, and Plethodus.

Bananogmius evolutus (Cope)

(This species was recently removed from the genus Bananogmius and renamed Pentanogmius evolutus by Taverne): A medium sized fish (4 to 6 feet) with a narrow, but deep body (like an Angel Fish) and jaws that had small, comb-like teeth. Most of the skeleton was bone and preserved well. A commonly found fossil is the palatine bone from the roof of the mouth. These have a pebbled surface that served as the base for hundreds of small, sharp teeth.

	LEFT: The exhibit specimen of Bananogmius (Pentanogmius) evolutus (FHSM VP-2182) in the collection of the Sternberg Museum. Although not fully displayed in this photograph of the reconstruction, the fish had a large, sail-like dorsal fin.
	LEFT: Bananogmius (Pentanogmius) evolutus FHSM VP-2117) in the collection of the Sternberg Museum of Natural History. The caudal fin (tail) is reconstructed. A close up view of the skull is HERE. A view of the teeth on the lower jaw of another specimen is HERE.

LEFT: The skull of a large Bananogmius (Pentanogmius) evolutus - KUVP 27815 in left lateral view collected from the Pierre Shale in 1971 by the Orville Bonner party.

RIGHT: The type specimen of Bananogmius ellisensis, preserved uncrushed in an ironstone concretion from the Blue Hill Shale Member of the Carlile Shale, Ellis County, Kansas (Middle Turonian in age).

Thryptodus:

Complete skulls of this strange, "battering-ram" fish are found rarely in the chalk, but mostly, only the rostrum at the tip of the skull survives. Unfortunately, the type specimen from the Kansas Chalk was destroyed in Germany during World War II.

LEFT: The skull of Thryptodus was heavily built, with a rostrum (the ethmoid bone) that is very massive. Another unusual feature is the flat surface at the anterior end. How was this fish using its head? Click HERE for a drawing of the skull of Thryptodus zitteli (from Loomis 1900). In Kansas, these fish are only found in the lower 1/4 of the Smoky Hill Chalk and apparently become extinct by the end of the Coniacian stage (about 86 mya).

Martinichthys:

These fish are somewhat mysterious in that they are only known to occur in Kansas, and only in a relatively narrow section of the chalk. There are only two partial skulls of these fish known and few vertebrae. One of them (KUVP 497) is shown here.

LEFT: Martinichthys "noses" or "snouts" are usually the only part of the fish that is preserved. This is a drawing the type specimen (AMNH FF_2131) in the American Museum of Natural History (adapted from O.P. Hay, 1903). Note that both Cope and Hay described / figured this specimen "upside-down."

The specimen was collected by Charles H. Sternberg in June, 1877 and described by Cope: Cope, E. D., 1877. On the genus Erisichthe. Bull. U. S. Geol. and Geog. Surv. iii, article xx. pp. 821-823.

These fish are usually represented in the fossil record only by a hard, blunt nose or rostrum. These rostra are often worn off at an angle as if the fish was using it to hammer at a hard substrate such as shells. The teeth are very small and comb-like in appearance. These fish only occur in a narrow zone in the lower 1/3 of the chalk. They are relatively rare (found only in Kansas) and there are less than 85 examples in collections. Most of the specimens are in the collections of the Sternberg Museum and the Museum of Natural History at the University of Kansas.

LEFT: FHSM VP-15567 - A recently discovered (2003), well-preserved Martinichthys brevis rostrum from the lower Smoky Hill Chalk of Gove County, KS.

Other Plethodids:

Relatively rare and unknown. These specimens are in the KU Museum of Natural History:

	LEFT: The skull of Ferrifrons rugosus Jordan 1924 (KUVP 296), the anterior portion of a complete specimen (damaged). It was almost 75 years later that this species was determined to be a plethodid (see Arratia and Chorn. 1998. Journal of Vertebrate Paleontology, 18(2): 301-314. The original specimen is 24.5 inches long and was collected by H.T. Martin about 4 miles northeast of Gove, in Gove County, KS.
	*LEFT: Niobrara encarsia* Jordon 1924 - This specimen was collected by H.T. Martin in Trego County. Another view of the type specimen (KUVP 179).**
	*LEFT: Zanclites xenurus* Jordon 1924 - This specimen was collected by H.T. Martin about 1/2 mile northeast of Gove, Gove County, KS. Another view of the type specimen (KUVP 52)**

Family?

Aethocephalichthys hyainarhinos

Headlamp Fish: A very unusual fish that is known only from the highly fused neurocrania that have been found in Mississippi, Kansas, South Dakota and New Zealand.

The specimen shown at right is from the Pierre Shale. It was found by Pam Everhart in 1995, and donated to the Sternberg Museum in 2004 (FHSM VP-15577). However, at least one specimen is known from the Smoky Hill Chalk in Gove County and is in the collection of the University of Kansas.

For more information, see: Fielitz, C., J. D. Stewart, and J. Wiffen, 1999. Aethocephalichthys hyainarhinos gen. et sp. nov., a new and enigmatic Late Cretaceous actinopterygian from North America and New Zealand, pp. 95-106, 7 fig., In Mesozoic Fishes 2 - Systematics and Fossil Record. Arrantia, G. and H-P. Shultze (eds.)

Order Elopiformes

Family Pachyrhizodontidae

Pachyrhizodontids

Larger members of this genus have a heavy skull, with large, conical, curved teeth. The remains of the jaws often have been mistaken for marine reptiles such as mosasaurs.

Pachyrhizodus minimus

A small predatory fish sometimes found complete with well preserved with scales and internal structure.

	LEFT: FHSM VP-326 - A very complete specimen in the Sternberg Museum of Natural History; collected by G. F. Sternberg in Trego County in 1949 and described by H.W. Miller (1957): *Intestinal casts in Pachyrhizodus, an Elopid fish, from the Niobrara Formation of Kansas. Kansas Academy of Science, Transactions 60(4): 399-401.*
	*RIGHT: FHSM VP-2282, a small Pachyrhizodus minimus* found by Ken Metzler in Ellis County (1968).**

Pachyrhizodus caninus

A medium sized predator, with long heavy jaws. The premaxillary of this species is relatively easy to identify because it has one or two large fangs set inside the outer row of teeth. Click here for photos of the skull and jaws of a very large Pachyrhizodus caninus specimen (FHSM VP-2189) in the collection of the Sternberg Museum.

ABOVE: A reconstructed skeleton of Pachyrhizodus caninus at the Rocky Mountain Dinosaur Resource Center.

RIGHT: The right maxilla and right dentary of Pachyrhizodus caninus.

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Pachyrhizodus leptopsis

A rare species in the lower chalk, differentiated from P. caninus by the shape of the teeth. While P. caninus teeth are round or oval in cross section, P. leptopsis teeth are distinctly fluted.

Order Elopiformes

Suborder Elopoidei

Family Apsopelicidae

Apsopelix anglicus: A small, relatively uncommon fish (less than 1.5 ft) from the lower Chalk.

LEFT: The exhibit specimen at the Sternberg Museum. Another Sternberg specimen is here

RIGHT: An Apsopelix anglicus specimen (KUVP-49402) in the University of Kansas collection. Collected by J. D. Stewart from Gove County in 1997.

Superorder Neoteleostei

Order Alepisauriformes

Cimolichthys nepaholica

Cimolichthys was a common, small to medium size predatory fish. This species has a triple row of teeth on the lower jaws and premaxillae, and no teeth on the maxillae. It also has very ornate vertebra, similar to those of Enchodus, a related genus. In addition, in some specimens, large scales or scutes are preserved along the lower portion of the body. This fish may have looked much like a modern barracuda or freshwater pike. Based on two finds of Cimolichthys with the undigested remains of their final meal still inside, it is known for certain that this fish fed on Enchodus petrosus.

LEFT: A complete specimen in the Museum of Natural History at the University of Kansas. (Click here for another specimen from the Denver Museum of Nature and Science) Additional pictures by Kenneth Jenkins here: Skull: Complete fish; vertebrae

Enchodontids:

Fish in the genus Enchodus were small to medium sized predators. Several species are well represented throughout the chalk and are commonly found as fossils. The characteristic that is most noticeable is the presence of large "fangs" at the front of the upper and lower jaws.

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Above: A drawing of Enchodus petrosus showing the oversized fangs which were typical of these fish. The upper fangs are slightly larger than the lower ones. Note that when the jaws are closed, the large palatine fangs of the upper jaw are between the large teeth on the lower jaws. This fish has also been called the "Saber-toothed Herring" because of the appearance of these unusually large, curved teeth. It is important to note, however, that Enchodus is not related to Herrings and in fact, is a member of the same Order as modern Salmon. It is possible that the fish may used it's unique teeth to feed on soft bodied animals like squid (Tusotuethids). This genus of fish survived the end of the Age of Dinosaurs by several million years and is well represented in the fossil record around the world.

Typical examples of Enchodus remains that are found in the Smoky Hill Chalk. Top row: Two palatine bones with partial fangs; Bottom row: two lower jaws.

Enchodus petrosus:

This fish was the largest of the Enchodontids found in the Smoky Hill Chalk (Niobrara Fm) of western Kansas.

LEFT: This is a picture of a fairly complete and unusually large set of Enchodus petrosus teeth found by the author in September, 2002. The fish would have been 4-5 feet long. It is little wonder that they have been referred to (incorrectly) as the "Saber-toothed Herrings" of the Cretaceous. They are more closely related to modern salmon.

Enchodus gladiolus

Another small predatory fish, with elongated fangs on the lower jaws and the palatine bones of the skull. E. gladiolus was a small sized predator, with palatine teeth that reached two inches in length. Pectoral fins are long and delicate, and may have given the fish the capability to 'fly' in a manner similar to modern flying fish.

LEFT: This specimen was found in the lower Smoky Hill Chalk by Pam Everhart and donated to the New Jersey State Museum.

RIGHT: The exhibit specimen of Enchodus gladiolus at the Sternberg Museum of Natural History. It appears to be missing the palatine tooth at the front of the upper jaw. These teeth were shed and replaced periodically as the fish grew larger and the length of the jaws increased.

Enchodus dirus - A small, relatively unknown species of Enchodus.

Apateodus

Apateodus sp. - Another small fish that is poorly known. This specimen (CMC VP 6941) at left was found by Pete Bussen of Wallace, KS, near the top of the Smoky Hill Chalk. It was donated to the Cincinnati Museum Center where I photographed it in 2003. Other views of this specimen are HERE, HERE, HERE, HERE and HERE

This specimen has recently been named as a new species (Apateodus busseni) in:

Fielitz, C. and Shimada, K. 2009. A new species of Apateodus (Teleostei: Aulopiformes) from the Upper Cretaceous Niobrara Chalk of western Kansas, U.S.A. Journal of Vertebrate Paleontology 28(3):650-658.

Family Dercetidae

Dercidids (Stratodus apicalis) - A relatively rare fish with a narrow, eel like body and numerous small teeth. The picture at below left shows the long, slender vertebral column of what had been a fairly complete specimen (EPC 1990-14) as found in the lower Smoky Hill Chalk.

LEFT: The disarticulated skull and jaws of a large Stratodus apicalis (KUVP 23) collected from Logan County by S. W. Williston.

RIGHT: Stratodus apicalis specimen as found in the Late Coniacian Smoky Hill Chalk (Gove County). Head is to the lower left in the photo. Hammer is 13 in / 33 cm.

LEFT: Vertebrae and jaw fragments from the specimen at above right.

RIGHT: A close-up of the jaw showing the fine, comb-like teeth. (Scale = mm)

Superorder Acanthopterygii

Order Beryciformes

Family Holocentridae Richardson (1846)

Genus Kansius Hussakof 1929

Kansius sternbergi

Near the middle of the chalk, large Inoceramid shells have been found with schools of small Holocentrid fish preserved inside. Sometimes numbering in the hundreds, these fish were apparently trapped inside the shell when the clam died and the shell closed. Although several new species have been found inside clam shells, most have not yet been described. The remains of one species, Kansius sternbergi (below), have been found inside and outside of clam shells.

This unusual association was first noted by G.F. Sternberg in 1930 on the basis of a group of "twenty or more" small fish discovered inside an inoceramid clam shell in northern Trego County by M.V. Walker. The fish averaged 3.5 inches long (his SP-225-30). Sternberg also mentioned a similar discovery from the Smoky Hill Chalk west of Webster, Kansas. These associations are most common in the early Santonian, near Marker Unit 8. .

LEFT: Kansius sternbergi - A small fish (about 3-4 inches) found rarely in the Chalk. Drawing from Hussakof (1929). Pictures of the type specimen (FHSM VP-19) in the collection of the Sternberg Museum are HERE and HERE.

RIGHT: A more complete specimen of Kansius sternbergi (FFHM 1972-128) on an inoceramid clam shell in the collection of the Fick Fossil and History Museum, Oakley, KS.

Superorder Paracanthopterygii

Order Polymixiiformes

Family Polymixiidae

Genus Omosoma Costa (1857)

Omosoma garretti - Omosoma was described first from Europe and the Middle East, but is found in greater numbers in the Smoky Hill Chalk (ibid., p. 357). Other specimens have been collected in Gove County, but preservation of the skeleton, especially the skull, is usually poor due to the small size. This small (4-7 cm) fish was first described from Kansas by Bardack (1976) from specimens found in the inside of an inoceramid shell from the Garrett Ranch in Trego County

LEFT: An unusual slab of chalk collected from Gove County in 1975 containing part of a school of Omosoma garretti FHSM VP-5115) on exhibit at the Sternberg Museum.

RIGHT: A detail from the Platyceramus platinus shell that the VP- 5115 specimen of Omosoma garretti was laying on.

Leptecodon rectus

ABOVE: The type specimen of Leptecodon rectus - KUVP 35.

S. W. Williston (1899, 1900) described a new genus and species of fish (Leptecodon rectus; KUVP 35) found inside an inoceramid (Platyceramus platinus) clam shell by H. T. Martin in 1895.

Three complete specimens of Omosoma garretti (KUVP 599016, 59017, 59018) were also associated with the new species. (See upper left of Plate 26) Age is Santonian.

ABOVE: A more recent (2004) picture of the type specimen of Leptecodon rectus - KUVP 35, in the collection of the University of Kansas Museum of Natural History. The specimen is laying on a piece of inoceramid shell.

RIGHT: It turns out that Leptocodon was an accomplished predator... both of the known specimens included stomach contents... the remains of a smaller Omosoma garretti was found inside the above specimen. Figure adapted from Figure 5 in: Stewart, J. D., 1990. Niobrara Formation symbiotic fish in inoceramid bivalves. p. 31-41 In S. Christopher Bennett (ed.), 1990 Society of Vertebrate Paleontology Niobrara Chalk excursion guidebook. Museum of Natural History and the Kansas Geological Survey, Lawrence, KS.

Caproberyx sp.

LEFT: A section of inoceramid shell (Platyceramus platinus) with the disarticulated remains of two or three small fish (Caproberyx sp.: KUVP 345) inside. Collected by H. T. Martin from the Smoky Hill Chalk (Gove County) in 1915.

Subclass Sarcopterygii

Coelacanths:

Until recently, there were no coelacanths known from the chalk. Coelacanths are well represented in the English Chalk (below RIGHT). The find of a partial skull by Pam Everhart in 1990 was the subject of a presentation (Stewart, J.D., et al., 1991) at the annual meeting of the Society of Vertebrate Paleontology and the Kansas Academy of Science annual meeting in 1995.

Since that time, another set of fragmentary remains has been found (J. D. Stewart, pers. comm. 1994). Although coelacanths are a very old family of fish, they are not extinct as once thought and are still found in the Indian Ocean near Madagascar, and in the East Indies.

LEFT: LACMNH 131958 - Jaws and palatoquadrate (See yellow highlighted area in figure at RIGHT.

Rare fish - There are several genera and species of fossil fish that are sometimes represented only by few remains or even just a single specimen from the chalk. These include: Trachichthyoides, Luxilites striolatus (KUVP 295), Paraliodesmus, and Belonostomus.

Continued on next page................................. A Field Guide to Fossils of the Smoky Hill Chalk: Part 3 - Marine Reptiles

Credits - Earl Manning provided information regarding the classification of fishes from the Smoky Hill Chalk.

BACK TO INDEX

A Field Guide to Fossils of the Smoky Hill Chalk

Part 2:

Sharks and Bony Fish (Continued from Part 1: Invertebrates)

Copyright © 2000-2009 by Mike Everhart

Latest update 09/18/2009

**Pictures of two Xiphactinus audax vertebrae are HERE and HERE (scale - mm)**