Dinosaurs Part 7

_By Prof. S.W. Williston._

Most great discoveries are due rather to a state of mind, if I may use such an expression, than to accident. The discovery of the immense dinosaur deposits in the Rocky Mountains in March, 1877, may truthfully be called great, for nothing in paleontology has equalled it, and that it was made by three observers simultaneously can not be called purely an accident. These discoverers were Mr. O. Lucas, then a school teacher, later clergyman; Professor Arthur Lakes, then a teacher in the School of Mines at Golden, Colorado; and Mr. William Reed, then a section foreman of the Union Pacific Railroad at Como, Wyoming, later the curator of paleontology of the University of Wyoming--even as I write this, comes the notice of his death,--the last. I knew them all, and the last two were long intimate friends.

In the autumn of 1878 I wrote the following:[19]

"The history of their discovery (the dinosaurs) is both interesting and remarkable. For years the beds containing them had been studied by geologists of experience, under the surveys of Hayden and King, but, with the possible exception of the half of a caudal vertebra, obtained by Hayden and described by Leidy as a species of _Poikilopleuron_, not a single fragment had been recognized. This is all the more remarkable from the fact that in several of the localities I have observed acres literally strewn with fragments of bones, many of them extremely characteristic and so large as to have taxed the strength of a strong man to lift them. Three of the localities known to me are in the immediate vicinity, if not upon the actual townsites of thriving villages, and for years numerous fragments have been collected by (or for) tourists and exhibited as fossil wood. The quant.i.ties. .h.i.therto obtained, though apparently so vast, are wholly unimportant in comparison with those awaiting the researches of geologists throughout the Rocky Mountain region. I doubt not that many hundreds of tons will eventually be exhumed." Rather a startling prophecy to make within eighteen months of their discovery, but it was hardly exaggerated.

It is impossible to say which of these three observers actually made the first discovery of Jura.s.sic dinosaurs; whatever doubt there is is in favor of Mr. Reed.

Professor Lakes, accompanied by his friend Mr. E.L. Beckwith, an engineer, was, one day in March, 1877, hunting along the "hogback" in the vicinity of Morrison, Colorado, for fossil leaves in the Dakota Cretaceous sandstone which caps the ridge, when he saw a large block of sandstone with an enormous vertebra partly imbedded in it. He discussed the nature of the fossil with his friend (so he told me) and finally concluded that it was a fossil bone. He had recently come from England and had heard of Professor Phillips' discoveries of similar dinosaurs there. He knew of Professor Marsh of Yale from his recent discoveries of toothed birds in the chalk of Kansas, and reported the find to him. As a result, the specimen, rock and all, was s.h.i.+pped to him by express at ten cents a pound! And Professor Marsh immediately announced the discovery of _t.i.tanosaurus_ (_Atlantosaurus_) _immanis_, a huge dinosaur having a probable length of one hundred and fifteen feet and unknown height. And Professor Lakes was immediately set at work in the "Morrison quarry" near by, whence comes the accepted name of these dinosaur beds in the Rocky Mountains. Professor Lakes once showed me the exact spot where he found his first specimen.

Mr. Lucas, teaching his first term of a country school that spring in Garden Park near Canon City, as an amateur botanist was interested in the plants of the vicinity. Rambling through the adjacent hills in search of them, in March, 1877, he stumbled upon some fragments of fossil bones in a little ravine not far from the famous quarry later worked for Professor Marsh. He recognized them as fossils and they greatly excited, not only his curiosity, but the curiosity of the neighbors. He had heard of the late Professor Cope and sent some of the bones to him, who promptly labelled them _Camarasaurus supremus_.

The announcement of these discoveries promptly brought Mr. David Baldwin, Professor Marsh's collector in New Mexico, to the scene. Only a few months previously he had discovered fossil bones in the red beds of New Mexico, the since famous Permian deposits. He naturally explored the same beds at Canon City, immediately below the dinosaur deposits, and soon found the still very problematical _Hallopus_ skeleton, at their very top, a specimen which after nearly forty years remains unique of its kind.

A few years earlier Professor Marsh, on his way east from the Tertiary deposits of western Wyoming, had stopped at Como, Wyoming, to observe the strange salamanders, or "fish with legs" as they were widely known, so abundant in the lake at that place, about whose transformations he later wrote a paper, perhaps the only one on modern vertebrates that he ever published. While he was there Mr. Carlin, the station agent, showed him some fossil bone fragments, so Mr. Reed told me, that they had picked up in the vicinity, and about which Professor Marsh made some comments. But he was so engrossed with the other discoveries he was then making that he did not follow up the suggestion. Had he done so the discovery of the "Jura.s.sic Dinosaurs"

would have been made five years earlier.

Mr. Reed, tramping over the famous Como hills after game--he had been a professional hunter of game for the construction camps of the Union Pacific Railroad--in the winter and spring of 1877, observed some fossil bones just south of the railway station that excited his curiosity. But he and Mr. Carlin did not make their discovery known to Professor Marsh till the following autumn, and then under a.s.sumed names, fearing that they would be robbed of their discovery. I was sent to Como in November of 1877 from Canon City. I got off the train at the station after midnight, and enquired for the nearest hotel--(the station comprised two houses only), and where I could find Messrs. Smith and Robinson. I was told that the section house was the only hotel in the place and that these gentlemen lived in the country and that there was no regular bus-line yet running to their ranch. A freshly opened box of cigars, however, helped clear up things, and I joined Mr. Reed the next day in opening "Quarry No. 1" of the Como hills. Inasmuch as the mercury in the thermometer during the next two months seldom reached zero--upward I mean--the opening of this famous deposit was made under difficulties. That so much "head cheese," as we called it, was s.h.i.+pped to Professor Marsh was more the fault of the weather and his importunities than our carelessness. However, we found some of the types of dinosaurs that have since become famous.

I joined Professor Lakes at the Morrison quarry in early September of 1877, and helped dig out some of the bones of _Atlantosaurus_. A few weeks later I was sent to Canon City to help Professor Mudge, my old teacher, and Mr. Felch, who had begun work there in the famous "Marsh Quarry". It was here that we found the type of _Diplodocus_.

The hind leg, pelvis and much of the tail of this specimen lay in very orderly arrangement in the sandstone near the edge of the quarry, but the bones were broken into innumerable pieces. After consultation we decided that they were too much broken to be worth saving--and so most of them went over into the dump. Sacrilege, doubtless, the modern collector will say, but we did not know much about the modern methods of collecting in those days, and moreover we were in too much of a hurry to get the new discoveries to Yale College to take much pains with them. I did observe that the caudal vertebrae had very peculiar chevrons, unlike others that I had seen, and so I attempted to save some samples of them by pasting them up with thick layers of paper.

Had we only known of plaster-of-paris and burlap the whole specimen might easily have been saved. Later, when I reached New Haven, I took off the paper and called Professor Marsh's attention to the strange chevrons. And _Diplodocus_ was the result.

[Ill.u.s.tration: Fig. 44.--The first dinosaur specimen found at Bone-Cabin Quarry. Hind limb of _Diplodocus_.]

My own connection with the discoveries of these old dinosaurs continued only through the following summer, in Wyoming, when we added the first mammals from the hills immediately back of the station, and the types of some of the smaller dinosaurs, and when we explored the vicinity for other deposits, on Rock Creek and in the Freeze Out Mountains.

How many tons of these fossils have since been dug up from these deposits in the Rocky Mountains is beyond computation. My prophecy of hundreds of tons has been fulfilled; and they are preserved in many museums of the world.

S.W. WILLISTON.

THE DINOSAURS OF THE BONE-CABIN QUARRY.[20]

_By Henry Fairfield Osborn._

One is often asked the questions: "How do you find fossils?" "How do you know where to look for them?" One of the charms of the fossil-hunter's life is the variety, the element of certainty combined with the gambling element of chance. Like the prospector for gold, the fossil-hunter may pa.s.s suddenly from the extreme of dejection to the extreme of elation. Luck comes in a great variety of ways: sometimes as the result of prolonged and deliberate scientific search in a region which is known to be fossiliferous; sometimes in such a prosaic manner as the digging of a well. Among discoveries of a highly suggestive, almost romantic kind, perhaps none is more remarkable than the one I shall now describe.

_Discovery of the Great Dinosaur Quarry._ In central Wyoming, at the head of a "draw," or small valley, not far from the Medicine Bow River, lies the ruin of a small and unique building, which marks the site of the greatest "find" of extinct animals made in a single locality in any part of the world. The fortunate fossil-hunter who stumbled on this site was Mr. Walter Granger of the American Museum expedition of 1897.

In the spring of 1898, as I approached the hillock on which the ruin stands, I observed, among the beautiful flowers, the blooming cacti, and the dwarf bushes of the desert, what were apparently numbers of dark-brown boulders. On closer examination, it proved that there is really not a single rock, hardly even a pebble, on this hillock; all these apparent boulders are ponderous fossils which have slowly acc.u.mulated or washed out on the surface from a great dinosaur bed beneath. A Mexican sheep-herder had collected some of these petrified bones for the foundations of his cabin, the first ever built of such strange materials. The excavation of a promising outcrop was almost immediately rewarded by finding a thigh-bone nearly six feet in length which sloped downward into the earth, running into the lower leg and finally into the foot, with all the respective parts lying in the natural position as in life. This proved to be the previously unknown hind limb of the great dinosaur _Diplodocus_.

In this manner the "Bone-Cabin Quarry" was discovered and christened.

The total contents of the quarry are represented in the diagram (not reprinted.) It has given us, by dint of six successive years of hard work, the materials for an almost complete revival of the life of the Laramie region as it was in the days of the dinosaurs. By the aid of workmen of every degree of skill, by grace of the acc.u.mulated wisdom of the nineteenth century, by the constructive imagination, by the aid of the sculptor and the artist, we can summon these living forms and the living environment from the vasty deep of the past.

_The Famous Como Bluffs._ The circ.u.mstances leading up to our discovery serve to introduce the story. From 1890 to 1897 we had been steadily delving into the history of the Age of Mammals, in deposits dating from two hundred thousand to three million years back, as we rudely estimate geological time. In the course of seven years such substantial progress had been made that I decided to push into the history of the Age of Reptiles also, and, following the pioneers, Marsh and Cope, to begin exploration in the period which at once marks the dawn of mammalian life and the climax of the evolution of the great amphibious dinosaurs.

In the spring of 1897 we accordingly began exploration in the heart of the Laramie Plains, on the Como Bluffs. On arrival, we found numbers of ma.s.sive bones strewn along the base of these bluffs, tumbled from their stratum above, too weather-worn to attract collectors, and serving only to remind one of the time when these animals--the greatest, by far, that nature has ever produced on land--were monarchs of the world.

Aroused from sleep on a clear evening in camp by the heavy rumble of a pa.s.sing Union Pacific freight-train[21], I shall never forget my meditations on the contrast between the imaginary picture of the great Age of Dinosaurs, fertile in cycads and in a wonderful variety of reptiles, and the present age of steam, of heavy locomotives toiling through the semi-arid and partly desert Laramie Plains.

So many animals had already been removed from these bluffs that we were not very sanguine of finding more; but after a fortnight our prospecting was rewarded by finding parts of skeletons of the long-limbed dinosaur _Diplodocus_ and of the heavy-limbed dinosaur _Brontosaurus_. The whole summer was occupied in taking these animals out for s.h.i.+pment to the East, the so-called "plaster method" of removal being applied with the greatest success. Briefly, this is a surgical device applied on a large scale for the "setting" of the much-fractured bones of a fossilized skeleton. It consists in setting great blocks of the skeleton, stone and all, in a firm capsule of plaster subsequently reinforced by great splints of wood, firmly drawn together with wet rawhide. The object is to keep all the fragments and splinters of bone together until it can reach the skilful hands of the museum preparator.

_The Rock Waves Connecting the Bluffs and the Quarry._ The Como Bluffs are about ten miles south of the Bone-Cabin Quarry; between them is a broad stretch of the Laramie Plains. The exposed bone layer in the two localities is of the same age, and originally was a continuous level stratum which may be designated as the "dinosaur beds;" but this stratum, disturbed and crowded by the uplifting of the not far-distant Laramie range of mountains and the Freeze Out Hills, was thrown into a number of great folds or rock waves. Large portions, especially of the upfolds, or "anticlines," of the waves, have been subsequently removed by erosion; the edges of these upfolds have been exposed, thus weathering out their fossilized contents, while downfolds are still buried beneath the earth for the explorers of coming centuries.

Therefore, as one rides across the country to-day from the bluffs to the quarry, startling the intensely modern fauna, the p.r.o.ng-horn antelopes, jack-rabbits, and sage-chickens, he is pa.s.sing over a vast graveyard which has been profoundly folded and otherwise shaken up and disturbed. Sometimes one finds the bone layer removed entirely, sometimes horizontal, sometimes oblique, and again dipping directly into the heart of the earth. This layer (dinosaur beds) is not more than two hundred and seventy-four feet in thickness, and is altogether of fresh-water origin; but as a proof of the oscillations of the earth-level both before and after this great thin sheet of fresh-water rock was so widely spread, there are evidences of the previous invasion of the sea (ichthyosaur beds) and of the subsequent invasion of the sea (mosasaur beds) in the whole Rocky Mountain region.

In traveling through the West, when once one has grasped the idea of continental oscillation, or submergence and emergence of the land, of the sequence of the marine and fresh-water deposits in laying down these pages of earth-history, he will know exactly where to look for this wonderful layer-bed of the giant dinosaurs; he will find that, owing to the uplift of various mountain-ranges, it outcrops along the entire eastern face of the Rockies, around the Black Hills, and in all parts of the Laramie Plains; it yields dinosaur bones everywhere, but by no means so profusely or so perfectly as in the two famous localities we are describing.

_How the Skeletons Lie in the Bluffs and Quarry._ At the bluffs single animals lie from twenty to one hundred feet apart; one rarely finds a whole skeleton, such as that of Marsh's _Brontosaurus excelsus_, the finest specimen ever secured here, which is now one of the treasures of the Yale museum. More frequently a half or a third of a skeleton lies together.

In the Bone-Cabin Quarry, on the other hand, we came across a veritable Noah's-ark deposit, a perfect museum of all the animals of the period. Here are the largest of the giant dinosaurs closely mingled with the remains of the smaller but powerful carnivorous dinosaurs which preyed upon them, also those of the slow and heavy-moving armored dinosaurs of the period, as well as of the lightest and most bird-like of the dinosaurs. Finely rounded, complete limbs from eight to ten feet in length are found, especially those of the carnivorous dinosaurs, perfect even to the sharply pointed and recurved tips of their toes. Other limbs and bones are so crushed and distorted by pressure that it is not worth while removing them.

Sixteen series of vertebrae were found strung together; among these were eight long strings of tail-bones. The occurrence of these tails is less surprising when we come to study the important and varied functions of the tail in these animals, and the consequent connection of the tail-bones by means of stout tendons and ligaments which held them together for a long period after death. Skulls are fragile and rare in the quarry, because in every one of these big skeletons there were no fewer than ninety distinct bones which exceeded the head in size, the excess in most cases being enormous.

[Ill.u.s.tration: Fig. 45.--COLLECTING DINOSAURS AT BONE-CABIN QUARRY.

a. The overlying soil and rocks are loosened with a pick and removed with team and sc.r.a.per down to the fossil layer.

b. The fossil layer is carefully prospected with small tools, chisels, awls and whisk brooms exposing the bones as they lie in the rocks.

c. The blocks containing the fossils are channelled around, plastered over top and sides, undercut and carefully turned over and the under side trimmed and plastered.

d. The blocks are then packed in boxes or crates with hay or any other available packing material.

e. Boxes are loaded on wagons and hauled across country to the railroad.

f. Boxes are finally loaded on cars and s.h.i.+pped through to New York City.]

The bluffs appear to represent the region of an ancient sh.o.r.eline, such conditions as we have depicted in the restoration of _Brontosaurus_ (fig. 22)--the sloping banks of a muddy estuary or of a lagoon, either bare tidal flats or covered with vegetation. Evidently the dinosaurs were buried at or near the spot where they perished.

The Bone-Cabin Quarry deposit represents entirely different conditions. The theory that it is the acc.u.mulation of a flood is, in my opinion, improbable, because a flood would tend to bring entire skeletons down together, distribute them widely, and bury them rapidly. A more likely theory is that this was the area of an old river-bar, which in its shallow waters arrested the more or less decomposed and scattered carca.s.ses which had slowly drifted down-stream toward it, including a great variety of dinosaurs, crocodiles, and turtles, collected from many points up-stream. Thus were brought together the animals of a whole region, a fact which vastly enhances the interest of this deposit.

_The Giant Herbivorous Dinosaurs._ By far the most imposing of these animals are those which may be popularly designated as the great or giant dinosaurs. The name, derived from _deinos_ terrible, and _sauros_ lizard, refers to the fact that they appeared externally like enormous lizards, with very long limbs, necks, and tails. They were actually remotely related to the tuatera lizard of New Zealand, and still more remotely to the true lizards.

No land animals have ever approached these giant dinosaurs in size, and naturally the first point of interest is the architecture of the skeleton. The backbone is indeed a marvel. The fitness of the construction consists, like that of the American truss-bridge, in attaining the maximum of strength with the minimum of weight. It is brought about by dispensing with every cubic millimeter of bone which can be spared without weakening the vertebrae for the various stresses and strains to which they were subjected, and these must have been tremendous in an animal from sixty to seventy feet in length. The bodies of the vertebrae are of hour-gla.s.s shape, with great lateral and interior cavities; the arches are constructed on the T-iron principle of the modern bridge-builder, the back spines are tubular, the interior is spongy, these devices being employed in great variety, and const.i.tuting a mechanical triumph of size, lightness, and strength combined. Comparing a great chambered dinosaurian (_Camarasaurus_) vertebra (see above) with the weight per cubic inch of an ostrich vertebra, we reach the astonis.h.i.+ng conclusion that it weighed only twenty-one pounds, or half the weight of a whale vertebra of the same bulk. The skeleton of a whale seventy-four feet in length has recently been found by Mr. F.A. Lucas of the Brooklyn Museum to weigh seventeen thousand nine hundred and twenty pounds. The skeleton of a dinosaur of the same length may be roughly estimated as not exceeding ten thousand pounds.

_Proofs of Rapid Movements on Land._ Lightness of skeleton is a walking or running or flying adaptation, and not at all a swimming one; a swimming animal needs gravity in its skeleton, because sufficient buoyancy in the water is always afforded by the lungs and soft tissues of the body. The extraordinary lightness of these dinosaur vertebrae may therefore be put forward as proof of supreme fitness for the propulsion of an enormous frame during occasional incursions upon land[22]. There are additional facts which point to land progression, such as the point in the tail where the flexible structure suddenly becomes rigid, as shown in the diagram of vertebrae below; the component joints are so solid and flattened on the lower surface that they seem to demonstrate fitness to support partly the body in a tripodal position like that of a kangaroo. I have therefore hazarded the view that even some of these enormous dinosaurs were capable of raising themselves on their hind limbs, lightly resting on the middle portion of the tail. In such a position the animal would have been capable not only of browsing among the higher branches of trees, but of defending itself against the carnivorous dinosaurs by using its relatively short but heavy front limbs to ward off attacks.

There are also indications of aquatic habits in some of the giant dinosaurs which render it probable that a considerable part of their life was led in the water. One of these indications is the backward position of the nostrils. Many, but not all, water-living mammals and reptiles have the nostrils on top of the head, in order to breathe more readily when the head is partly immersed. Another fact of note, although perhaps less conclusive, is the fitness of the tail for use while moving about in the water, if not in rapid swimming.

The great tail, measuring from twenty-eight to thirty feet, was one of the most remarkable structures in these animals, and undoubtedly served a great variety of purposes, propelling while in the water, balancing and supporting and defending while on land. In _Diplodocus_ it was most perfectly developed from its muscular base to its delicate and whip-like tip, perhaps for all these functions.

_The Three Kinds of Giant Dinosaurs._ It is very remarkable that three distinct kinds of these great dinosaurs lived at the same time in the same general region, as proved by the fact that their remains are freely commingled in the quarry.

What were the differences in food and habits, in structure and in gait, which prevented that direct and active compet.i.tion between like types in the struggle for existence which in the course of nature always leads to the extermination of one or the other type? In the last three years we have discovered very considerable differences of structure which make it appear that these animals, while of the same or nearly the same linear dimensions, did not enter into direct compet.i.tion either for food or for territory.

The dinosaur named _Diplodocus_ by Marsh is the most completely known of the three. Our very first discovery in the Bone-Cabin Quarry gave us the hint that _Diplodocus_ was distinguished by relatively long, slender limbs, and that it may be popularly known as the "long-limbed dinosaur." The great skeleton found in the Como Bluffs enabled me to restore for the first time the posterior half of one of these animals estimated as sixty feet in length, the hips and tail especially being in a perfect state of preservation. A larger animal, nearer seventy feet in length, including the anterior half of the body, and still more complete, was discovered about ten miles north of the quarry, and is now in the Carnegie Museum in Pittsburg. Combined, these two animals have furnished a complete knowledge of the great bony frame.