CHAPTER XI.

COLLECTING DINOSAURS.

HOW AND WHERE THEY ARE FOUND.

The visitor who is introduced to the dinosaurs through the medium of books and pictures or of the skeletons exhibited in the great museums, finds it hard--well nigh impossible--to realize their existence. However willing he may be to accept on faith the reconstructions of the skeletons, the restorations of the animals and their supposed environment, it yet remains to him somewhat of a fairy-tale, a fanciful imaginative world peopled with ogres and dragons and belonging to the unreal "once upon a time" which has no connection with the ever present workaday world in which we live. Birds and squirrels, rabbits and foxes belong to this real world because he has seen them in his walks through the woods; even elephants and rhinoceroses, though his acquaintance be limited to menagerie specimens, seem fairly real--although one recalls the farmer's comment on first seeing a giraffe in the Zoological park: "There aint no sich animal." But dinosaurs--one easily realizes the state of mind that prompts the inquiry so often made by visitors to the Dinosaur Hall:--"they make these out of plaster, don't they?" So far as is consistent with good taste, the aim of the American Museum has been to enable the visitor to see for himself how much of plaster reconstruction there is to each skeleton, and to explain in the labels what the basis was for the reconstructed parts.

_How They are Found._ But to the collector these extinct animals are real enough. As he journeys over the western plains he sees the various living inhabitants thereof, birds and beasts, as well as men, pursuing their various modes of life; here and there he comes across the scattered skeletons or bones of modern animals lying strewn upon the surface of the ground or half buried in the soil of a cut bank. In the shales or sandstones that underlie the soil he finds the objects of his search, skeletons or bones of extinct animals, similarly disposed, but buried in rock instead of soft soil, and exposed in cañons and gullies cut through the solid rock. Each rock formation, he knows by precept and experience, carries its own peculiar fauna, its animals are different from those of the formation above and from those in the formation below. Days and weeks he may spend in fruitless search following along the outcrop of the formation, through rugged badlands, along steep cañon walls, around isolated points or buttes, without finding more than a few fragments, but spurred on by vivid interest and the rainbow prospect of some new or rare find. Finally perhaps, after innumerable disappointments, a trail of fragments leads up to a really promising prospect. A cautious investigation indicates that an articulated skeleton is buried at this point, and that not too much of it has "gone out" and rolled in weathered fragments down the slope. For the tedious and delicate process of disinterring the skeleton from the rock he will need to keep ever in mind the form and relations of each bone, the picture of the skeleton as it may have been when buried. The heavy ledges above are removed with pick and shovel, often with help of dynamite and a team and scraper. As he gets nearer to the stratum in which the bones lie the work must be more and more careful. A false blow with pick or chisel might destroy irreparably some important bony structure. Bit by bit he traces out the position and lay of the bones, working now mostly with awl and whisk-broom, uncovering the more massive portions, blocking out the delicate bones in the rock, soaking the exposed surfaces repeatedly with thin "gum" (mucilage) or shellac, channeling around and between the bones until they stand out on little pedestals above the quarry floor. Then, after the gum or shellac has dried thoroughly and hardened the soft parts, and the surfaces of bone exposed are further protected by pasting on a layer of tissue paper, it is ready for the "plaster jacket." This consists of strips of burlap dipped in plaster-of-paris and pasted over the surface of each block until top and sides, all but the pedestal on which it rests, are completely cased in, the strips being pressed and kneaded close to the surface of the block as they are laid on. When this jacket sets and dries the block is rigid and stiff enough to lift and turn over; the remains of the pedestal are trimmed off and the under surface is plastered like the rest. With large blocks it is often necessary to paste into the jacket, on upper or both sides, boards, scantling or sticks of wood to secure additional rigidity. For should the block "rack," or become shattered inside, even though no fragments were lost, the specimen would be more or less completely ruined.

The next stage will be packing in boxes with straw, hay or other materials, hauling to the railway and shipment to New York.

Arrived at the Museum, the boxes are unpacked, each block laid out on a table, the upper side of its plaster jacket softened with water and cut away, and the preparation of the bone begins. Always it is more or less cracked and broken up, but the fragments lie in their natural relations. Each piece must be lifted out, thoroughly cleaned from rock and dirt, and the fractured surfaces cemented together again. Parts of bones, especially the interior, are often rotted into dust while the harder outer surface is still preserved. The dust must be scraped out, the interior filled with a plaster cement, and the surface pieces re-set in position. Very often a steel rod is set into the plaster filling the interior of a bone, to secure additional strength.

After this preparation is completed, each part being soaked repeatedly with shellac until it will absorb no more, the bones can be handled and laid out for study or exhibition. Then, if they are to be mounted for a fossil skeleton, comes the work of restoring the missing parts. For this a plaster composition is used.

Where only parts of one side are missing the corresponding parts of the other side are used for model; where both sides are missing, other individuals or nearly related species may serve as a guide. But it is seldom wise to attempt restoration of a skeleton unless at least two-thirds of it is present; composite skeletons made up of the remains of several or many individuals, have been attempted, but they are dangerous experiments in animals so imperfectly known as are most of the dinosaurs. There is too much risk of including bones that pertain to other species or genera, and of introducing thereby into the restoration a more or less erroneous concept of the animal which it represents. The same criticism applies to an overly large amount of plaster restoration.

In some instances the missing parts of a skeleton are not restored, because, even though but a small part be gone, we have no good evidence to guide in its reconstruction. This gives an imperfect and sometimes misleading concept of what the whole skeleton was like, but it is better than restoring it erroneously. Usually with the more imperfect skeletons, a skull, a limb or some other characteristic parts may be placed on exhibition but the remainder of the specimen is stored in the study collections.

_Where They are Found._ The chief dinosaur localities in this country are along the flanks of the Rocky Mountains and the plains to the eastward, from Canada to Texas. Not that dinosaurs were any more abundant there than elsewhere. They probably ranged all over North America, and different kinds inhabited other continents as well. But in the East and the Middle West, the conditions were not favorable for preserving their remains, except in a few localities. Formations of this age are less extensive, especially those of the delta and coast-swamps which the dinosaurs frequented. And where they do occur, they are largely covered by vegetation and cannot be explored to advantage. In the arid Western regions these formations girdle the Rockies and outlying mountain chains for two-thousand miles from north to south, and are extensively exposed in great escarpments, river cañons and "badland" areas, bare of soil and vegetation and affording an immense stretch of exposed rock for the explorer. Much of this area indeed is desert, too far away from water to be profitably searched under present conditions, or too far away from railroads to allow of transportation of the finds at a reasonable expense. Fossils are much more common in certain parts of the region, and these localities have mostly been explored more or less thoroughly. But the field is far from being exhausted. New localities have been found and old localities re-explored in recent years, yielding specimens equal to or better than any heretofore discovered. And as the railroad and the automobile render new regions accessible, and the erosion of the formations by wind and rain brings new specimens to the surface, we may look forward to new discoveries for many years to come.

In other continents, except in Europe, there has been but little exploration for dinosaurs. Enough is known to assure us that they will yield faunæ no less extensive and remarkable than our own. We are in fact only beginning to appreciate the vast extent and variety of these records of a past world.

In a preceding chapter it was shown that the chief formations in which dinosaur remains have been found belong to the end of the Jurassic and the end of the Cretacic periods. The Jurassic dinosaur formations skirt the Rockies and outlying mountain ranges but are often turned up on edge and poorly exposed, or barren of fossils. The richest collecting ground is in the Laramie Plains, between the Rockies and the Laramie range in south-central Wyoming, but important finds have also been made in Colorado and Utah. The Cretaceous Dinosaur formations extend somewhat further out on the plains to the eastward, and the best collecting regions thus far explored are in eastern Wyoming, central Montana and in Alberta, Canada.

THE FIRST DISCOVERY OF DINOSAURS IN THE WEST.

_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 quantities hitherto 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 Jurassic 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 shipped to him by express at ten cents a pound! And Professor Marsh immediately announced the discovery of _Titanosaurus_ (_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 Cañon 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 Cañon 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 "Jurassic 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 assumed names, fearing that they would be robbed of their discovery. I was sent to Como in November of 1877 from Cañon 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 shipped 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 Cañon 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.

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 pass 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 accumulated 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 accumulated 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 circumstances 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 massive 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 passing 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 shipment 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 prong-horn antelopes, jack-rabbits, and sage-chickens, he is passing 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 vertebræ 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.