Sternberg 1900-2

The Sharks of Kansas.

Editor POPULAR SCIENCE:

     In 1891, while conducting an expedition in the Chalk of Western Kansas for the Palaeontological Museum of Munich, under the direction of Dr. Von Zittel, its famous director, I discovered in the chalk of Hackberry Creek, Gove Co., some very small flattened disks, slightly hi-concave, that were in their original position. With pick and shovel, I removed the loose material above the floor in which the skeleton lay buried.
     As I continued my labor and got further into the bluff beyond the action of frost, the rock became harder and to my great delight, after I had swept the floor, I found a continuous line of these disks, beginning near the end of the tail, where they were about a quarter of an inch wide, increasing in size to the region of the neck, where they were four inches wide. Then, owing to the angle of pressure, they became narrower and thicker. The occipital condyle was attached to the peculiar bones of the skull. These bones were very different from those of bony fishes, as if in old age bony material had been deposited in the cartilage of which the skeletons of sharks are composed. The great plates that evidently covered the roof and floor of the mouth were armed with horrid teeth, arranged in concentric rows, the larger ones measuring about two inches in length from the lance-like point to end of root. The cutting edges were smooth and sharp as a knife, and must have proved a terrible machine, when the vise-like jaws closed upon an unfortunate victim that this torment of other life of his day had captured.
     I fully understood also, that I had made a discovery that would gratify the scientific world. As I believed then and still believe, such a specimen of a fossil shark was never seen before or since, The great German museum in which many of our ablest paleontologists, Cope, Marsh, Baur, and a host of others have studied, is justly proud of this specimen, which is full 25 feet long, with 250 teeth, chiefly in or near their original position. This fact is shown by the careful study and research bestowed upon it and kindred forms, by Mr. Chas. R. Eastman, whose inaugural address before the faculty of Ludwig-Maximilian University of Munich, for the degree of Doctor of Philosophy, were published in Stuttgart in 1894, describing this now famous shark, Oxyrhina mantelli of Agassiz. Forty-two pages of text are devoted to the results of his study.

The value of such discoveries will be appreciated when we realize that the cartilaginous skeletons of sharks decay before petrifaction can take place; consequently the forms and structure of fossil sharks can only be guessed at. The teeth in great numbers strew the old ocean beds for countless ages. It will be noticed that only the centra of vertebræ and plates of the skull were discovered, no arches or spines or other parts of the skeleton. The soft spongy centra had been crushed nearly flat by the pressure of the heavy strata above. These disks had been noticed and collected years ago by us early explorers in the Kansas Chalk; but we were unable to place them where they belonged until a lucky find of fragments bearing teeth.
     Since 1891 I have searched carefully for another individual, but loose and scattered teeth or centra of vertebræ were the only rewards I received, This season, however, I have been again favored by the discovery of 17 continuous vertebræ connected with the peculiar bones of the skull, and the teeth-bearing plates below. They were preserved in disintegrated chalk, crossed by seams of gypsum, the bones broken into fragments. I found 17 of these fragments bearing teeth, and many others from which the teeth had fallen out. As I believe I have saved all the pieces, the ossified part of the skull can be restored.
     This will prove, also, of great interest to science, as this specimen belonged to another genus from the one mentioned above. The teeth are broad and flat, slightly recurved, with delicately serrated edges And it represents, I believe, the second best specimen so far taken from the Chalk of Kansas, or the Niobrara Group of the Cretaceous. These teeth range in size from less than ¼ to 7/8 of an inch across the roots, one measuring 1 1/8 inches from recurved point to end of opposite root. There are 132 teeth preserved, some so small as to be hardly visible, others quite large; some are evidently young ones. These beautiful teeth during life must have been used with scissor-like action, cutting the living prey finer then any modern meat-cutter.
     I judge from the cervical vertebræ (the disks measuring 2 1/2 inches across), this species must have been nearly as large as the Munich specimen.

CHAS. H. STERNBERG.

Kansas Sharks - A photographic essay of shark teeth from the Lower Permian to the Upper Cretaceous.

Hattin, D. E., 1982. Stratigraphy and depositional environment of the Smoky Hill Chalk Member, Niobrara Chalk (Upper Cretaceous) of the type area, western Kansas. Kansas Geological Survey Bulletin 225, 108 pp.

Williamson, T. E., J. I. Kirkland and S. G. Lucas. 1993. Selachians from the Greenhorn cyclothem ("Middle" Cretaceous: Cenomanian-Turonian), Black Mesa, Arizona, and the paleogeographic distribution of Late Cretaceous selachians. J. Paleon. 67(3):447-474.

Williamson, T. E., S. G. Lucas and J. I. Kirkland. 1990. The Cretaceous elasmobranch Ptychodus decurrens Agassiz from North America. Geobios 24(5):595-599.

Williamson, T. E. and S. G. Lucas. 1992. Selachian fauna from the Upper Cretaceous (Coniacian) El Vado Sandstone Member of the Mancos Shale, San Juan Basin, New Mexico. New Mexico Geological Society Annual Field Conference, Guidebook 43, pp. 17-19.

Williamson, T. E., S. G. Lucas, and R. Pence. 1989. Selachians from the Hosta Tongue of the Point Lookout Sandstone (Upper Cretaceous, Santonian), central New Mexico. New Mexico Geological Society Guidebook, 40th Field Conference, Southeastern Colorado Plateau, pp. 239-245.

Zidek, J., 1976. Oklahoma Paleoichthyology Part V: Chondrichthyes. Oklahoma Paleontology Notes, 36(5):175-192, Oklahoma Geol. Surv., Norman, OK.

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