A few marine plants are found, but no land vegetation, except an occasional fragment of fossil wood. The absence of terrestrial plants is the more remarkable, as extinct birds and numerous amphibians indicate that dry land must have existed. This wood was, in a few instances, bored before fossilization by some small animal. This might have been done by the larva of an insect (a "borer") when the tree was living, or later by a terdo* when the trunk floated in the water. In either case, it showed that the Cretaceous vegetation was subject to the same enemies as that of the present period. Some of this wood was in a charred condition, and would burn freely. Other specimens were changed to almost pure silica, the cavities studded with crystals of quartz. In one case, a log weighing five hundred pounds had all conditions of the transformation; a portion had the appearance of soft decayed wood, which crumbled in the handling, and other parts rang like flint under the hammer. Occasionally specimens were converted into chalcedony, but the annual growth of the wood distinctly remained. In a single instance we detected the fibrous structure of the palm.
* A teredo, T. tibialis, has been found in the Cretaceous of Alabama.
It is rather singular that we have never found the leaves so common in our Dakota, and which are equally numerous in the Tertiary of Colorado, as islands must have existed in the Cretaceous ocean, as the resting and breeding homes of the birds.
A new and rare form of Crinoid, first found by Prof. Marsh, in the Uinta Mountains, was in a few instances procured by our party. It is the only Crinoid known to the American Cretaceous. It is described by G. B. Grinnell in the Am. Jour. of Science and Art, July, 1876, page 81, as Uinta-crinus socialis.
Of mollusks, the most common are Ostrea congesta and Inoceramus problematicus. Less common, but still seen in many strata, are fragments of the large Haploscapha, with occasionally a perfect specimen. Another large bivalve we have never seen described, measures from thirty to thirty-three inches in length. It is thin, with a transverse fibre like the Inocerami, and always lies crushed flat in numerous fragments nearly in their normal position; a few Gryphea; also fragments, frequently weighing ten pounds, of a large Hippurites, near H. Toncasianus. Near Sheridan we recently discovered a bed of Baculites, and on referring them to Prof. F. B. Meek for identification, he decides that they are B. anceps, not before found nearer than New Mexico. In his kind response to my inquiries, dated Nov. 21, 1876, he writes:
"One fact in regard to your specimens, however, is curious to me. All the other forms like this I have ever seen from any part of the Far West, come from our Nos. 4 and 5;* while all of the other species of anything yet known from those upper rocks is distinct from anything found in Nos. 2 or 3.** Can it be possible that you might have found this in an outlier of Nos. 4 or 5? It has the shell substance well preserved like the fossils of those upper beds, while those in the lower beds are usually casts."
* Fort Pierre and Fort Hill groups.
** Fort Benton and Niobrara.
The situation of the Baculites was, however, clearly in the Niobrara, as the characteristic fish and saurians were found fifteen or twenty-five feet above, in the bluffs not two hundred yards distant. It is also a common incident to find the shell substance of Inoceramus problematic, etc., in excellent preservation in Wallace county. Almost all the shells and fragments are covered in part by the Ostrea congesta, which abound everywhere,
But the great feature of this division of the Cretaceous consists in its varied and rare forms of the vertebrate fossils. Four seasons, of six or seven months each, (1874, '75, '76, '77,) have been spent by myself, with from two to five assistants, in collecting these vertebrates for Yale College.
The least interesting are the fish, which have, however, given us many new species and some new genera. The small ones are nearly entire, but the larger ones are represented only by well preserved portions of the skeletons. Teeth of Salachians are quite common. At one locality over four hundred were collected in an area of thirty inches, and apparently from the jaws of one individual — Ptycodus mortine — and all in excellent preservation.
Quite recently I had the good fortune to find the teeth, cartilaginous jaw, and vertebrae of a shark — Galeocerdo falcatus — three portions, which, I think, have never hitherto been found together. The flat, porous vertabrae had occasionally been collected, but we had been unable to give them their generic name. The teeth were frequently procured.
Prof. Cope, in his "Cretaceous Vertebrata," has described thirty-six species of fish, and some twenty others have quite recently been found. In 1872, only twenty-four species had been collected from Kansas. The most unique is a new genus (three species), which has a snout appended to the skull like the sword of the sword-fish, but conical in shape, composed of a compact bundle of fibers. In the largest species, this snout is about fifteen inches long, and one and a half in diameter at the base. Prof. Cope has a representation of a portion of the jaws in Plate XLVIII, Figs. 3-8, under the name of Erisicthic nitida. But, unfortunately, his specimen did not then embrace the snout or much of the skull, so that a correct idea of the fish is not obtained from his description. But in Hayden's Report for 1876, after procuring better specimens, he has given a correct description.
In individuals, the fish were quite numerously represented. In the season of 1875, our party saw, according to my note book, 1,207 specimens, without counting the teeth of sharks. Many of these, however, were so fragmentary that we did not collect them. The genera Portheus and Empo were most abundant.
Several species of marine turtle have been obtained. One described by Cope, (Protostega gigas) was fifteen feet in the expanded flipper. The type is embryonic. This is seen in the structure of the ribs, which are more free and detached from the dermal plates of the carapace than those now living. Other species, however, from the same horizon, did not show any embryonic features. One, one-fourth as long, had its ribs closely united with the plates, and in other characteristics had the semblance of a mature type.
A small species was somewhat common whose size was about that of a fresh-water turtle now found in Kansas. Some species, which Prof. Marsh has not yet had time to examine, will undoubtedly be new to science.
Less in number than the fish, but of more importance, are the reptiles of the crocodile and Saurian type. My note book shows four hundred and seventy-six specimens seen by our party in 1875, of which one-half might be called good, and some of them equal, if not superior, to anything previously found in Europe or America. Prof. Cope, in the work above quoted, has made a list of all the genera and species then known in the Cretaceous, which shows fifty-one hitherto described, of which Europe furnishes but four, and Kansas twenty-six. To this latter number must be added eight or ten which have been discovered by our party within three years, which are now in possession of Prof. Marsh, who will soon publish a technical description of them. New Jersey comes next, furnishing fifteen species.
Although this formation extends quite widely into Nebraska, but few vertebrates have been found within that State. They have been collected most abundantly in the Saline and Smoky Hill valleys. Let it be borne in mind that this deposit is never over two hundred feet in thickness.
Our labors during four years past have added much to the knowledge previously obtained in regard to the structure of this class of reptiles, particularly of the smaller bones and hind limbs. The collections from Kansas in the possession of Prof. Marsh, will leave little to be needed in the study of the anatomy of Saurians, as they are more full and complete than any in Europe.
The Saurians are of all sizes. One from Jewell county, an Enaliasaur, was about seventy feet long, while two species are less than six feet. Most frequently they are from twenty-five to forty feet in length.
During the summer of 1878 Prof. Snow found, in Gove county, a fine specimen of a Saurian, (a Liodon, resembling Liodon dispelor) which for the first time contained the print of the hide or skin of the animal. The scales are similar to those of a snake, in regular position and clearly defined. Solitary scales had been obtained before by Prof. Marsh, but their true character was uncertain. Aside from the discovery of the skin, the specimen contains over two hundred bones in most excellent preservation. For a more particular description see the article of Prof. Snow in the Proceedings of the Kansas Academy of Science for 1878.
Specimens are frequently represented by a few bones washed out and lying exposed. The best are obtained by finding a projecting fragment, and then following the skeleton into the compact shale or chalk. This sometimes requires much hard labor but it is the most satisfactory, as the fossils are, in such cases, in a better state of preservation. A single specimen has cost us as much as six days' labor. As the bones are sometimes friable, drawings of the best specimens are made as soon as uncovered, before removal. The fossilizing material is lime, combined with a little silica; the minute striae and muscle markings are in most excellent preservation. But in some cases they are impregnated with gypsum or iron (sulphide and oxide) when the fine texture and characteristic markings are destroyed, and the fossils comparatively worthless.
Our researches were confined to the slides and ravines, which had expose chalk and shales. These constituted but a small portion of the country, but slowly being enlarged by the action of the elements. Miles of these exposures yielded us nothing, and again a small area furnished good specimens. The inference is, that the animals frequented favorite haunts, to the exclusion of larger areas. Three long seasons spent on this territory, besides the labors of other collectors, have nearly exhausted the present supply of rare fossils. As future washings occur, more specimens may be obtained.
Coprolites of fish and Saurians are frequently found, containing the remains of the food of the animal. Small fish appear to be the most common food; but in one instance a rare crustacean was found preserved in this way. The coprolites are not so hard as those of Europe, being a little firmer than chalk and finer-grained.
The following analysis of a Saurian coprolite, not containing bone, from Wallace county, is by George E. Patrick, Professor of Chemistry in the University of Kansas:
| " | Moisture | 1.22 | |
| Organic matter | .42 | ||
| Oxide of iron and alumina | 29.99 | ||
| Lime | 24.31 | ||
| Alkalies, small amount undetermined. | |||
| Silica (combined) | .19 | ||
| Phosphoric acid | 34.88 | ||
| Carbonic acid | 7.05 | ||
| Sulphuric acid | 1.92 | ||
| 99.98 | " |
In some cases the undigested organic matter (bones) was one-fourth of the whole weight.
We sometimes find remains of the indigestible portions of food between the ribs where the stomach is situated. In the Plesiosauri we found another interesting feature, showing an aid to digestion, similar to many living reptiles and some birds. This consisted of well worn silicious pebbles, from one-fourth to one-half inch in diameter. They were the more curious, as we never found such pebbles in the chalk or shales of the Niobrara. How far the Saurians wandered to collect them is a perplexing problem. Their structure does not indicate much ability to crawl on land, and yet it is probable that they frequented some of the islands of the old Cretaceous ocean for that and other purposes. As such substances remain in stomachs of low organization for a long time, the visits to dry land would not necessarily have been very frequent. Sharks' teeth were sometimes found in the remains of food, showing the taste of the Saurians and their high carnivorous natures. On the other hand, we frequently found evidence that the sharks returned the compliment, for bones of Saurians were found with the marks of the sharp serrate teeth of Galeocerdo, which could not have been made unless the bones were still fresh and unhardened. That such huge reptiles must have had fierce contests with each other is also apparent. The type of the head and teeth would indicate this. But in addition it was no uncommon thing to find Saurian ribs which had been broken and again united while the animal lived. In one case a more serious injury occurred. In a fine specimen, one of the most perfect collected by us, we discovered that the animal had received a very serious injury to his back, which he had outlived. Five of the vertebrae had been fractured so seriously as to destroy many of the spinous processes, after which it had healed, but the whole had grown together, (anchylosed) so as to lose the natural form of the separate bones and become a confused, firm mass. The enemy that could have thus injured a monster thirty-five or forty feet in length, and whose jaws of defense were thirty-three inches long, must have made a fierce contest. When we know that the largest (Brimosaurus, Leidy) was seventy feet long, with a head six feet, those of half that size should avoid an encounter, and those only six feet in length might have been swallowed whole.
The Niobrara of Kansas also affords the only Pterodactyls yet known in the United States, and we believe in America.* They differ widely from those of the
* Since the above was written, my young friend, S. W. Williston, of Manhattan, has found several fragments of a small specimen in Wyoming.
Old World in the absence of teeth, and general structure of the head; the latter is much more elongated and beak-like. On the great divergence from the European type, Prof. Marsh* has based a new sub-order, Pterodontia, of two genera, and described six species, viz.: Pteranodon ingens, P. occidentalis, P. velox, P. longiceps, P. comptus, and Nyctosaurus gracilis. Cope** has also described two species: Ornithochirus umbrosus, and O. harpia. But it is possible that one or two species of the two authorities may be identical. They average much larger than those of Europe, several species being from twenty to twenty-five feet in extent of wing. Fragments of the bones are frequent, but usually poorly preserved, strongly contrasting in this respect with the other vertebrate remains. The long bones, being very hollow, were compressed to the thickness of one-tenth of an inch, and exceedingly friable. The articulations, being thicker, are firm and in better preservation. Bones of the head were more rare. In one instance (of P. ingens), I uncovered a hand, with the four long bones of the wing-finger, as they lay in place, and found them measuring respectively twenty-four and a half inches (24 1/2), twenty and three-quarter inches (20 3/4) fourteen and a half (14 1/4) and nine (9) inches; or five feet eight and three-quarter inches (5ft. 8 3/4 in.), in total length. The width of the first, as it lay compressed to one-tenth of an inch, was about two inches. My note book shows seventy-two (72) individual specimens seen in 1875; but little more than half of which could be saved, as much as we valued this rare fossil. In some instances on opening a piece of chalk, the outline could be distinctly seen, but the bone crumbled to dust. In 1876, we were more successful, and the Museum of Yale College has a collection exceedingly rich, particularly in the smaller and frailer bones, not well represented in the European species.
* Am. Jour. of Science, III, p. 360, June, 1871; XI, p. 507, June, 1875; and XII, p, 479, Dec., 1876.
** Transactions Amer. Philosophical Society, March 1st, 1872.
In Dr. Cones' Key to North American Birds, published in 1873, Prof. Marsh has given a list of the fossil birds from the Cretaceous of North America, at which time thirteen species were known, all first described by himself. Of these, five are from the Niobrara beds of Kansas. To this we have added two species, making (as some others are not yet fully identified) at least seven from Kansas. Five of these are so anomalous as to be provided with jaws and teeth. These Prof. Marsh described as a sub-class, Odontornithes***. In the Odontolcae we have birds of the largest class of aquatics, measuring five to six feet in height. The teeth are set in grooves in the jaws. The wings are very rudimentary, too weak for flight. The Odontotormae, on the other hand, are small, with strong wings, giving great power of flight, and the teeth are set in sockets. And what is more singular, the vertebrae are biconcave, like a fish, but still retaining the bone structure of the bird. Bones of the legs and wings were of the usual bird structure. The best preserved (Ichthornis despar) was found by the writer and first described by Prof. Marsh in the American Journal of Science, Vol. IV, p. 314, and illustrated in Vol. X, p. 402. Professor Marsh has now in press a monograph on the Cretaceous birds, where all will be fully described and illustrated.
*** Am. Jour. of Science, November, 1875, p. 403.
