This Age of Primitive Man, this Age of the Horse, the Lion, and the Elephant, like all other historical or geological "ages," lasted longer in some places than in others, and, instead of having sharply defined limits, merged gradually into the preceding and succeeding ages.
Moreover--in exact a.n.a.logy with other divisions of time, all of which, however useful, are essentially artificial--we must constantly remember that the perspective changes utterly with the point of view. All paleontological terms of time are necessarily terms chiefly of convenience, which have and express a real intrinsic value, but which cannot be sharply defined. Miocene, Pliocene, Pleistocene, and Recent are such terms. They are arbitrarily chosen bits of terminology to express successive stages of the world"s growth, and therefore successive and varying faunas. They are not equivalent in time to one another; the more remote the age from our own the greater is the length of time we include therein. "Recent" denotes a short period of time compared to "Pleistocene," and "Pleistocene" a short period compared to "Pliocene." If there are on this earth intelligent beings at a time in the future as remote from our day as our day is from the Pliocene, they will certainly consider "Recent" and "Pleistocene" as one short period.
All the beast faunas and all the human cultures from the eras of the chinless Heidelberg and Piltdown men to our own time will seem in that remote perspective practically contemporaneous. Similarly, when we try to grasp life as lived even in such, geologically, near-by time as any portion of the Pleistocene, we cannot be sure of the exact time-parallelism of closely related faunas in different parts of the world, nor can we, in many cases, tell whether certain species were really contemporaneous or whether they were successive. Of the general paleontological facts, of the general aspects of the various faunas in various parts of the world, during some roughly indicated period of geologic time, we may be reasonably sure. But when we speak with more minuteness, we speak doubtfully, and at any moment new discoveries may unsettle theories by upsetting what we have supposed to be facts.
In considering what is in this chapter set forth these conditions must be kept in mind. When I speak of what I have myself seen or of the tools, carvings, and skeletons dug from the ground by competent observers, I speak of facts; but as yet the explanations of these facts must be accepted only as hypotheses, at least in part. Just as the elephant, wild horse, and lion exist in Africa to-day, and have disappeared from Europe and the two Americas thousands or tens of thousands of years ago, so it may well be that they had died out in North America ages before they had disappeared from the other end of the western hemisphere. Again, in North America, it is as yet quite impossible to be sure as to the exact succession, or contemporaneity of all of the many extinct species of horse and elephant. It is with our present knowledge equally impossible to be sure of the exact time relations between any given North American fauna and the Eurasiatic fauna most closely resembling it. Moreover, as yet we have only the vaguest idea of the duration of even modern geologic time; good observers vary as to whether a given period covers hundreds of thousands or only tens of thousands of years.
This does not impair the value of the general picture which we can make in our minds. It is not essentially different from what is the case in history. If we speak of the Graeco-Roman world from the days of Aristides to those of Marcus Aurelius, we outline a historical period which has a real unity, and of which all the parts are bound together by real ties and real resemblances. Nevertheless, there were sharp differences in the successive cultures of this period; even the two centuries which intervened, say, between Miltiades and Demetrius Poliorketes, or between Marius and Trajan, showed such differences. Dealing roughly with the period as a whole, it would not be necessary to try to draw all the distinctions and make all the qualifications that would be essential to minutely accurate treatment; such treatment would merely mar the outlines of a general sketch. The same thing is, of course, true of an outline sketch of what our present knowledge shows of man"s most wide-spread beast a.s.sociates, when he had begun, in forms not very different from those of the lower savages to-day, to spread over the world"s surface.
Therefore it is necessary to remember that in dealing even with such a recent chapter of paleontological discovery as that concerned with early man and the great four-footed creatures that were his contemporaries, our general picture can rarely pretend to more than general accuracy. It is only in prehistoric and protohistoric Europe that the early career of "h.o.m.o sapiens" and his immediate predecessors has been worked out in sufficient detail to give even the roughest idea of its successive stages, and of the varying groups of great beasts with which at the different stages man was a.s.sociated. This is because the record has been better preserved, and more closely studied in Europe than elsewhere; for it seems fairly certain that it is in Eurasia, in the palaearctic realm, that there took place the development of the more or less ape-like predecessors of man and then of man himself. It is in Eurasia that all of the remains of man"s immediate predecessors have been found--from the Javan pithecanthropus which can only doubtfully be called human, to the Piltdown and Heidelberg men, who were undoubtedly human, but who were so much closer than any existing savage to the beasts that (unless our present imperfect knowledge proves erroneous) they can hardly be deemed specifically identical with modern h.o.m.o sapiens. Even the more modern Neanderthal men are probably not ancestral to our own stock. It is in Europe, following on these predecessors of existing man, that we find the skeletons, the weapons and tools, and the carvings of existing man in his earliest stages; and mingled with his remains those of the strange and mighty beasts which dwelt beside him in the land. Probably these European forefathers of existing man came from a stock which had previously gone through its early human and prehuman stages in Asia. But we only know what happened in Europe. There was a slow, halting, and interrupted but on the whole steady development in physical type--sometimes the type itself gradually changing, while sometimes it was displaced by a wholly different type of wholly different blood.
Roughly parallel with this was a corresponding development in cultural type. Probably from the earliest times, and certainly in late times, development or change in physical type was often wholly unrelated to development or change in culture. Sometimes the cultural change was an autochthonous development. Sometimes it was due to a more or less complete change in blood, owing to the immigration of a strong alien type of humanity. Sometimes it was due to the adoption of an alien culture.
Many good observers nowadays, judging from the facts at present accessible, are inclined to think that the American Indian stocks were the first human stocks that peopled the western hemisphere, that they are by blood nearest of kin to certain race-elements still existing in northeastern Asia--representing the only inhabitants of northeastern Asia when man first penetrated from there to northwestern America--and that more remotely they may be kin to certain late Palaeolithic men of Europe. But much of the American Indian culture was essentially a Neolithic culture, seemingly from the beginning. In places--Peru, Maya-land, the Mexican plateau--it at times developed into a civilization equally extraordinary for its achievements and for its shortcomings and evanescence; but it never developed a metal epoch corresponding to, say, the bronze age of the Mediterranean, and although the small camel, the llama, was tamed in South America, in North America, the ox, sheep, white goat, and reindeer were never made servants of man, as befell so many corresponding beasts of Eurasia.
In this last respect the American Indians stayed almost on the level of the African tribes, whose native civilization was otherwise far less advanced. The African buffalo is as readily tamed as its Asiatic brother; the zebra was as susceptible of taming as the early wild horse and a.s.s; the eland is probably of all big ruminants the one that most readily lends itself to domestication. But none of them was tamed until tribes owning animals which had been tamed for ages appeared in Africa; and then the already-tamed animals were accepted in their stead. The a.s.ses, cattle, sheep, and goats of Asia are now the domestic animals of the negroes and of the whites in Africa, merely because it is easier, more profitable, and more convenient to deal with animals already accustomed for ages to the yoke of domestic servitude than to again go through the labor incident to changing a wild into a tame beast.
It is probable that during the immense stretch of time which in Europe covered the growth of the various successive Palaeolithic, and finally Neolithic, cultures--the "old-stone" ages during which man used stone implements which he merely chipped and flaked, and the "new-stone" age in which he ground and polished them--there happened time and again what has happened in the history and prehistory of man in Africa and North America. One of the incidents in this parallelism is the way in which the inhabitants accepted animals already trained and brought from elsewhere rather than attempt to train the similar beasts of their own forests. Doubtless the reason why the European bison is not a domestic animal is exactly the same as the reason why the American bison and African buffalo are not domestic animals. The northern European hunting savages were displaced or subjugated by, or received a higher culture from, tribes bringing from Asia or from the Mediterranean lands the cattle they had already tamed. The same things happened, in Africa south of the Sahara while it was still shrouded from civilized vision, and in America since the coming of the European.
These hunting savages existed for ages, for hundreds of thousands of years, in Europe. During this period of time--immense by historic standards, yet geologically a mere moment--many different human types succeeded one another. The climate swung to and from glacial to subtropical; fauna succeeded fauna. One group of species of big beasts succeeded another as the climate and plant life changed; and then itself gave place to a third; and perhaps once more resumed its ancient place as the physical conditions again became what they once had been. At certain periods the musk-ox, the reindeer, the woolly rhinoceros, and the hairy mammoth, together with huge cave-bears, were found; at other periods southern forms of elephant and rhinoceros, and such tropical creatures as the hippopotamus, replaced the beasts of the snow land.
Horses of different species were sometimes present in incredible numbers. There were species of wild cattle, including the European bison, and the urus or aurochs--spoken of by Caesar, and kin to, and doubtless partly ancestral to, the tame ox. The cave-lion, perhaps indistinguishable from the modern African lion, was the most formidable beast of prey. I say "perhaps" indistinguishable, for we cannot be quite certain. Some of the races of cave-dwelling men were good artists, and carved spirited figures of mammoth, rhinoceros, bison, horse, reindeer, and bear on ivory, or on the walls of caves. The big lion-like cats appear only rarely in these pictures.
In most cases the arctic and warm-temperate or near-tropical animals supplanted one another only incompletely as the waves of life advanced and receded when the climate changed. This seems a rather puzzling conjunction. The explanation is twofold. When the climate changes, when it becomes warmer, for instance, northern creatures that once were at home in the lowlands draw off into the neighboring highlands, leaving their old haunts to newcomers from the south, while nevertheless the two faunas may be only a few miles apart; just as in Montana and Alberta moose and caribou in certain places were found side by side with the p.r.o.ngbuck. Moreover, some species possess an adaptability which their close kin do not, and can thrive under widely different temperature conditions. A century ago the hippopotamus was found in the temperate Cape Colony, close to mountain ranges climatically fit for the typical beasts of north-temperate Eurasia. In Arizona at the present day mammals and birds of the Canadian fauna live on the mountain tops around the bases of which flourish animals characteristic of the tropical Mexican plateau; the former having been left stranded on high mountain islands when, with the retreat of the glaciers, the climate of the United States grew warmer and the tide of southern life-forms swept northward over the lowlands. Under such conditions the same river deposits might show a combination of utterly different faunas. Moreover, some modern animals are found from the arctics to the tropics. The American lynx extends, in closely connected forms, from the torrid deserts of Mexico to arctic Alaska; so does the mountain-sheep. The tiger flourishes in the steaming Malay forests and in snowy Manchuria. I have found the cougar breeding in the frozen, bitter midwinter among the high Rockies, in a country where snow covered the ground for six months, and where the caribou would be entirely at home; and again in Brazil under the equator, in the atmosphere of a hot-house. There were periods, during the ages before history dawned, but when man had long dwelt in Europe, in which herds of reindeer may have roamed the French and English uplands within sight of rivers wherein the hippopotamus dwelt as comfortably as he recently did at the Cape of Good Hope.
Some of the more recent of these European hunting savages--those who were perhaps in part our own forefathers, or who perhaps were of substantially the same ethnic type as the men of the older race strains in northeastern Asia, and even possibly of the American Indians--and many of their more remote predecessors were contemporaries of the lion, the horse, and the elephant. Different species of horse and elephant succeeded one another. The earlier ones were contemporaries of the hippopotamus and of not only the lion but the sabretooth. When the hairy elephant, the mammoth, was present, the fauna also often included the cave-lion, cave-hyena, cave-bear, wolf, boar, woolly rhinoceros, many species of deer (including the moose and that huge fallow deer, the Irish elk), horses, and the bison and the aurochs. The mammoth and woolly rhinoceros died out so recently that their carca.s.ses are discovered preserved in the Siberian ice, and the undigested food in their stomachs shows that they ate northern plants of the kinds now common, and the twigs of the conifers and other trees which still flourish in the boreal realm of both hemispheres.
The lion was doubtless the most dreaded foe of the ancient European, just as he is to this day of certain African tribes. The Palaeolithic hunters slaughtered myriads of wild horses, just as the ebony-hued hunters of Africa now slaughter the zebra and feast on its oily flesh.
The spirited carvings and sketches of the hairy mammoth by the later Palaeolithic cave-dwellers show that the elephant of the cold northlands had impressed their imaginations precisely as the hairless elephant of the hot south now impresses the imaginations of the tribes that dwell under the vertical African sun. The rhinoceros and wild cattle of the pine forests played in their lives the part played in the lives of our contemporaries, the hunting tribes of Africa, by the rhinoceros and the buffalo--the African wild ox--which dwell among open forests of acacias and drink from palm-bordered rivers. They saw no animal like that strange creature, the African giraffe; and several kinds of deer took the place of the varied species of bovine ruminants which, in popular parlance, we group together as antelopes.
Substantially the fauna of mighty beasts which furnished the means of livelihood, and also constantly offered the menace of death, to our European forefathers--or to the predecessors of our forefathers--was like that magnificent fauna which we who have travelled among the savages of present-day Africa count it one of our greatest pleasures to have seen. During the ages when the successive races of hunter-savages dwelt in Europe a similar magnificent fauna of huge and strange beasts flourished on all the continents of the globe except in Australia. In Europe it vanished in prehistoric times, when man had long dwelt in the land. In Africa south of the Sahara, and partially in spots of Asia, it has persisted to this day. In North America it died out before, or perhaps, as regards the last stragglers, immediately after, the coming of man; in South America it seems clear that it survived, at least in places, until he was well established.
The three abundant and conspicuous beasts, all three typical of the great mammalian fauna which was contemporary with the prehistoric human hunters, and all three common to all the continents on which this great mammalian fauna was found, were the lion--using the name to cover several species of huge horse-killing and man-killing cats; the elephant, including several totally different species, among them the mammoth and mastodon; and the horse, including numerous widely different species. Together with these three universally distributed animals were many others belonging to types confined to certain of the continents.
Rhinoceros were found in Europe, Asia, and Africa (they had once flourished in North America but had died out long before man appeared on the globe). Camels were found in Asia, in South America, and especially in North America, which was their centre of abundance and the place where they had developed. Wild oxen were found in all the continents except South America; deer everywhere except in true Africa, zoogeographical Africa, Africa south of the Sahara. The pigs of the Old World were replaced by the entirely different peccaries of the New World. Sheep, goats, and goat-antelopes lived in Eurasia and North America. Most of the groups of big ruminants commonly called "antelopes"
are now confined to Africa; but it appears that formerly various representatives of them reached America. The giraffe through this period was purely African; the hippopotamus has retreated to Africa, although in the period we are considering its range extended to Eurasia. In South America were many extraordinary creatures totally different from one another, including ground-sloths as big as elephants. Two or three outlying representatives of the ground-sloths had wandered into North America; but elsewhere there were no animals in any way resembling them. The horse, the lion, and the elephant were the three striking representatives of this vast and varied fauna which were common to all five continents.
The North American fauna of this type reached its height about the time--extending over many scores of thousands of years--when successive ice ages alternated with long stretches of temperate or subtropical climate throughout the northern hemisphere. During the period when this great North American fauna flourished hunter-savages of archaic type lived amid, and partly on, the great game of Europe. But, as far as we know, men did not come to America until after, or at the very end of, the time when these huge gra.s.s-eaters and twig-eaters, and the huge flesh-eaters which preyed on them, vanished from the earth, owing to causes which in most cases we cannot as yet even guess.
Much the most striking and interesting collection of the remains of this wonderful fauna is to be found near one of our big cities. On the outskirts of Los Angeles, in southern California, are asphalt deposits springing from petroleum beds in the shales below. The oil seeping up to the surface has formed shallow, spread-out pools and, occasionally, deep pits covered with water. In part of the area these pits and pools of tar have existed for scores of thousands or hundreds of thousands of years, since far back in the Pleistocene. They then acted as very dangerous and efficient mammal traps and bird traps--and now continue so to act, for the small mammals and the birds of the neighborhood still wander into them, get caught in the sticky substance, and die, as I have myself seen. Moreover the tar serves as a preservative of the bones of the creatures that thus perish. In consequence some of the ancient pits and pools are filled with immense ma.s.ses of the well-preserved bones of the strange creatures that were smothered in them ages ago.
Nowhere else is there any such a.s.semblage of remains giving such a nearly complete picture of the fauna of a given region at a given time.
A striking peculiarity is that the skeletons of the flesh-eaters far surpa.s.s in number the skeletons of the plant-eaters. This is something almost unique, for of course predatory animals are of necessity much less numerous than the animals on which they prey. The reversal in this case of the usual proportions between the skeletal remains of herbivorous and carnivorous beasts and birds is due to the character of the deposits. The tar round the edges of the pools or pits hardens, becomes covered with dust, and looks like solid earth; and water often stands in the tar pits after rain, while at night the shallow pools of fresh tar look like water. Evidently the big grazing or browsing beasts now and then wandered out on the hard asphalt next the solid ground, and suddenly became mired in the soft tar beyond. Probably the pits in which water stood served as traps year after year as the thirsty herds sought drink. Then each dead or dying animal became itself a lure for all kinds of flesh-eating beasts and birds, which in their turn were entrapped in the sticky ma.s.s. In similar manner, thirty years ago on the Little Missouri, I have known a grizzly bear, a couple of timber-wolves, and several coyotes to be attracted to the carca.s.s of a steer which had bogged down in the springtime beside an alkali pool.
Another result of the peculiar conditions under which the skeletons acc.u.mulated is that an unusually large number of very old, very young, and maimed or crippled creatures were entrapped. Doubtless animals in full vigor were more apt to work themselves free at the moment when they found they were caught in the tar; and, moreover, a wolf or sabretooth which was weakened by age or by wounds received in encounter with its rivals, or with some formidable quarry, and which therefore found its usual prey difficult to catch, would be apt to hang around places where carca.s.ses, or living creatures still feebly struggling, offered themselves to ravenous appet.i.tes.
The plant remains in these deposits show that the climate and vegetation were substantially those of California to-day, although in some respects indicating northern rather than southern California. There were cypress-trees of a kind still common farther north, manzanita, juniper, and oaks. Evidently the region was one of open, gra.s.sy plains varied with timber belts and groves. It has been said that to support such a fauna the vegetation must have been much more luxuriant than in this region at present. This is probably an error. The great game regions of Africa are those of scanty vegetation. Thick forest holds far less big animal life. Crossing the sunny Athi or Kapiti plains of East Africa, where the few trees are th.o.r.n.y, stunted acacias and the low gra.s.s is brown and brittle under the drought, the herds of zebra, hartebeest, wildebeest, and gazelle are a perpetual delight and wonder; and elephant, rhinoceros, and buffalo abounded on them in the days before the white man came. On the Guaso Nyero of the north, and in the Sotik, the country was even drier at the time of my visit, and the character of the vegetation showed how light the normal rainfall was. The land was open, gra.s.sy plain, or was thinly covered with thorn scrub, with here and there acacia groves and narrow belts of thicker timber growth along the watercourses, and in the Sotik gnarled gray olives. Yet the game swarmed. We watched the teeming ma.s.ses come down to drink at the shrunken rivers or at the dwindling ponds beside which our tents were pitched. As the line of the safari walked forward under the brazen sky, while we white men rode at the head with our rifles, the herds of strange and beautiful wild creatures watched us, with ears p.r.i.c.ked forward, or stood heedless in the thin shade of the trees, their tails switching ceaselessly at the biting flies. In wealth of numbers, in rich variety and grandeur of species, the magnificent fauna we then saw was not substantially inferior to that which an age before dwelt on the California plains.
This Pleistocene California fauna included many beasts which persisted in the land until our own day. There were cougars, lynxes, timber-wolves, gray foxes, coyotes, bears, p.r.o.nghorn antelopes and black-tail or white-tail deer nearly, or quite, identical with the modern forms. They were the same animals which I and my fellow ranchmen hunted when, in the early eighties of the last century, our branded cattle were first driven to the Little Missouri. They swarmed on the upper Missouri and the Yellowstone when Lewis and Clark found the bison and wapiti so tame that they would hardly move out of the way, while the grizzly bears slept on the open plains and fearlessly attacked the travellers. But in the Pleistocene, at the time we are considering, the day of these modern creatures had only begun. The contents of the tar-pits show that the animals named above were few in number, compared to the great beasts with which they were a.s.sociated.
The giant among these Pleistocene giants of California, probably the largest mammal that ever walked the earth, was the huge imperial elephant. This mighty beast stood at least two feet higher than the colossal African elephant of to-day, which itself is bigger than the mammoth, and as big as any other extinct elephant. The curved tusks of the imperial elephant reached a length of sixteen feet. A herd of such mighty beasts must have been an awe-inspiring sight--had there been human eyes to see it. Nor were they the only representatives of their family. A much more archaic type of elephant, the mastodon, flourished beside its gigantic cousin. The mastodon was a relatively squat creature, standing certainly four feet shorter than the imperial elephant, with comparatively small and slightly curved tusks and a flatter head. Enormous numbers of mastodons ranged over what is now the United States, and the adjacent parts of Canada and Mexico. The mastodons represented a stage farther back in the evolutionary line than the true elephants, and in the Old World they died out completely before the latter disappeared even from Europe and Siberia. But in North America, for unknown reasons, they outlasted their more highly developed kinsfolk and rivals, and there is some ground for believing that they did not completely disappear until after the arrival of man on this continent.
The elephant stock developed in the Old World, and it is probable that the true elephants were geologically recent immigrants to America, coming across the land bridge which then connected Alaska and Siberia.
In California they encountered the big descendants of other big immigrants, which had reached North America by another temporary land bridge, but from another continent, South America. These were the ground-sloths, giant edentates, which reached an extraordinary development in the southern half of our hemisphere, where distant and diminutive relatives--tree-sloths, ant-eaters, armadillos--still live.
The most plentiful of these California ground-sloths, the mylodon, was about the size of a rhinoceros; an unwieldy, slow-moving creature, feeding on plants, and in appearance utterly unlike anything now living.
Together with these great beasts belonging to stocks that in recent geologic time had immigrated hither from the Old World and from the southern half of the New World was another huge beast of remote native ancestry. This was a giant camel, with a neck almost like that of a giraffe. Camels--including llamas--developed in North America. Their evolutionary history certainly stretched through a period of two or three million--perhaps four or five million--years on this continent, reaching back to a little Eocene ancestor no bigger than a jack-rabbit.
Yet after living and developing in the land through these untold ages, over a period inconceivably long to our apprehension, the camels completely died out on this continent of their birth, although not until they had sent branches to Asia and South America, where their descendants still survive.
Two other gra.s.s-eating beasts, of large size--although smaller than the above--were also plentiful. One, a bison, bigger, straighter-horned and less specialized than our modern bison, represented the cattle, which were among the animals that pa.s.sed to America over the Alaskan land bridge in Pleistocene time.
The other was a big, coa.r.s.e-headed horse, much larger than any modern wild horse, and kin to the then existing giant horse of Texas, which was the size of a percheron. The horses, like the camels, had gone through their developmental history on this continent, the earliest ancestor, the little four-toed "dawn horse" of the Eocene, being likewise the size of a jack-rabbit. Through millions of years, while myriads of generations followed one another, the two families developed side by side, increasing in size and seemingly in adaptation to the environment.
Each stock branched into many different species and genera. They spread into the Old World and into South America. Then, suddenly,--that is, suddenly in zoologic sense--both completely died out in their ancient home, and the horses in South America also, whereas half a dozen very distinct species are still found in Asia and Africa.
All these great creatures wandered in herds to and fro across the gra.s.sy Californian plains and among the reaches of open forest. Preying upon them were certain carnivores grimmer and more terrible than any now existing. The most distinctive and seemingly the most plentiful was the sabretooth. This was a huge, squat, short-tailed, heavily built cat with upper canines which had developed to an almost walrus-like length; only, instead of being round and blunt like walrus tusks, they were sharp, with a thin, cutting edge, so that they really were ent.i.tled to be called sabres or daggers. Whether the creature was colored like a lion or like a tiger or like neither, we do not know, for it had no connection with either save its remote kinship with all the cats. The sabretooth cats, like the true cats, had gone through an immensely long period of developmental history in North America, although they did not appear here as early as the little camels and horses. Far back across the ages, at or just after the close of the Eocene--the "dawn age" of mammalian life--certain moderate-sized or small cat-like creatures existed on this continent, doubtless ancestral to the sabretooth, but so generalized in type that they display close affinities with the true cats, and even on certain points with the primitive dog creatures of the time. Age followed age--Oligocene, Miocene, Pliocene. The continents rose and sank and were connected and disconnected. Vast lakes appeared and disappeared. Mountain chains wore down and other mountain chains were thrust upward. Periods of heat, during which rich forests flourished north of the arctic circle, were followed by periods of cold, when the glacial ice-cap crept down half-way across the present temperate zone. Slowly, slowly, while the surface of the world thus changed, and through innumerable reaches of time, the sabretooth cats and true cats developed along many different lines in both the Old World and the New. One form of sabretooth was in Europe with the b.e.s.t.i.a.l near-human things who were the immediate predecessors of the first low but entirely human savages. It was in the two Americas, however, that the sabretooth line culminated, immediately before its final extinction, in its largest and most formidable forms. This California sabretooth was not taller than a big cougar or leopard, but was probably as heavy as a fair-sized lion. Its skeletal build is such that it cannot have been an agile creature, apt at the pursuit of light and swift prey. By rugged strength and by the development of its terrible stabbing and cutting dagger teeth, that is, by sheer fighting ability, it was fitted for attack upon and battle with the ma.s.sive herbivores then so plentiful. It must indeed have been a fearsome beast in close grapple. Doubtless with its sharp, retractile claws it hung onto the huge bodies of elephant, camel, and ground-sloth, of horse and bison, while the sabres were driven again and again into the mortal parts of the prey and slashed the flesh as they withdrew. It seems possible that the mouth was opened wide and stabbing blows delivered, almost as a rattlesnake strikes with raised fangs. Vast numbers of sabretooth skeletons have been found in the asphalt; evidently the strange, formidable creature haunted any region which held attraction for the various kinds of heavy game on which it preyed.
The only other carnivore as abundant as the sabretooth was a giant wolf.
This was heavier than any existing wolf, with head and teeth still larger in proportion. The legs were comparatively light. Evidently, like the sabretooth, this giant wolf had become specialized as a beast of battle, fitted to attack and master the bulky browsers and grazers, but not to overtake those that were smaller and swifter. The ma.s.sive jaws and teeth could smash heavy bones and tear the toughest hide; and a hungry pack of these monsters, able to a.s.sail in open fight any quarry no matter how fierce or powerful, must have spread dire havoc and dismay among all things that could not escape by flight.
There were two still larger predatory species, which were much less plentiful than either the wolf or the sabretooth. One was a short-faced cave-bear, far larger than even the huge Alaskan bear of to-day.
Doubtless it took toll of the herds; but bears are omnivorous beasts, and not purely predatory in the sense that is true of those finished killers, the wolves and big cats. Unlike the wolves and cats, bears were geologically recent immigrants to America.
The other was a true cat, a mighty beast; bigger than the African lion of to-day; indeed, perhaps the biggest and most powerful lion-like or tiger-like cat that ever existed. Seemingly it was much rarer than the sabretooth; but it is possible that this seeming rarity was due to its not lurking in the neighborhood of pools and licks but travelling more freely over the wastes, being of a build fit not only for combat but for an active and wandering life. It is usually spoken of as kin to the African lion, a decidedly smaller beast. It is possible that its real kinship lies with the tiger. The Manchurian form of the tiger is an enormous beast, and a careful comparison of the skulls and skeletons may show that it equals in size the huge western American cat of Pleistocene times. I have already spoken of the fact that in many cases it is almost impossible to distinguish the lion and tiger apart by the bones alone; and it may be that the exact affinities of these recently extinct species with living forms cannot be definitely determined. But during historic and prehistoric times the lion has been a beast of western Eurasia and of Africa. The tiger, on the contrary, is and has been a beast of eastern Asia, and apparently has been spreading westward and perhaps southward--that it was not as ancient an inhabitant of jungle-covered southern India as the elephant and leopard seems probable from the fact that it is not found in Ceylon, which island in all likelihood preserves most of the southern Indian fauna that existed prior to its separation from the mainland. Moreover, the finest form of tiger exists in cold northeastern Asia. In Pleistocene times this portion of Asia was connected by a broad land bridge with western America, where the mighty American cat then roved and preyed on the herds of huge plant-eating beasts. We know that many Asiatic beasts crossed over this land bridge--the bears, bison, mountain-sheep, moose, caribou, and wapiti, which still live both in Asia and North America, and the mammoth and cave-bears, which have died out on both continents.
It is at least possible--further investigation may or may not show it to be more than possible--that the huge Pleistocene cat of western America was the collateral ancestor of the Manchurian tiger. Whether it was another immigrant from Asia, or a developed form of some big American Pliocene cat, cannot with our present knowledge be determined.
Surely the thought of this vast and teeming, and utterly vanished wild life, must strongly appeal to every man of knowledge and love of nature, who is gifted with the imaginative power to visualize the past and to feel the keen delight known only to those who care intensely both for thought and for action, both for the rich experience acquired by toil and adventure, and for the rich experience obtained through books recording the studies of others.
Doubtless such capacity of imaginative appreciation is of no practical help to the hunter of big game to-day, any more than the power to visualize the long-vanished past in history helps a practical politician to do his ordinary work in the present workaday world. The governor of Gibraltar or of Aden, who cares merely to do his own intensely practical work, need know nothing whatever about any history more ancient than that of the last generation. But this is not true of the traveller. It is not even true of the politician who wishes to get full enjoyment out of life without shirking its duties. He certainly must not become a mere dreamer, or believe that his dreams will help him in practical action.
But joy, just for joy"s sake, has its place too, and need in no way interfere with work; and, of course, this is as true of the joy of the mind as of the joy of the body. As a man steams into the Mediterranean between the African coast and the "purple, painted headlands" of Spain, it is well for him if he can bring before his vision the galleys of the Greek and Carthaginian mercantile adventurers, and of the conquering Romans; the boats of the wolf-hearted Arabs; the long "snakes" of the Norse pirates, Odin"s darlings; the stately and gorgeous war craft of Don John, the square-sailed ships of the fighting Dutch admirals, and the lofty three-deckers of Nelson, the greatest of all the masters of the sea. Aden is like a furnace between the hot sea and the hot sand; but at the sight of the old rock cisterns, carved by forgotten hands, one realizes why on that coast of barren desolation every maritime people in turn, from the mists that shroud an immemorial antiquity to our own day of fevered materialistic civilization, has seized Aden Bay--Egyptian, Sabean, Byzantine, Turk, Persian, Portuguese, Englishman; and always, a few miles distant, in the thirsty sands, the changeless desert folk have waited until pride spent itself and failed, and the new power pa.s.sed, as each old power had pa.s.sed, and then the merciless men of the waste once more claimed their own.
Gibraltar and Aden cannot mean to the unimaginative what they mean to the men of vision, to the men stirred by the hero tales of the past, by the dim records of half-forgotten peoples. These men may or may not do their work as well as others, but their gifts count in the joy of living. Enjoyment the same in kind comes to the man who can clothe with flesh the dry bones of bygone ages, and can see before his eyes the great beasts, hunters and hunted, the beasts so long dead, which thronged the Californian land at a time when in all its physical features it had already become essentially what it still continues to be.
The beast life of this prehistoric California must be called ancient by a standard which would adjudge the Egyptian pyramids and the Mesopotamian palace mounds and the Maya forest temples to be modern. Yet when expressed in geologic terms it was but of yesterday. When it flourished the Eurasian hunting savages were in substantially the same stage of progress as the African hunting savages who now live surrounded by a similar fauna. On the whole, taking into account the number, variety, and size of the great beasts, the fauna which surrounded Palaeolithic man in Europe was inferior to that amid which dwell the black-skinned savages of equatorial Africa. Even Africa, however, although unmatched in its wealth of antelopes, cannot quite parallel, with its lion, elephant, and zebras, the lordlier elephant, the great horse, and the huge cat of the earlier Californian fauna; and the giraffe, the hyena, the rhinoceros, and the hippopotamus do not quite offset the sabretooth, the giant wolf, the mastodon, the various species of enormous ground-sloths, and the huge camel; the bison and buffalo about balance each other.
There were no human eyes to see nor human ears to hear what went on in southern California when it held an animal life as fierce and strange and formidable as mid-Africa to-day. The towering imperial elephants and the burly mastodons trumpeted their approach one to the other. The great camels, striding noiselessly on their padded feet, pa.s.sed the clumsy ground-sloths on their way to water. The herds of huge horses and bison drank together in pools where the edges were trodden into mire by innumerable hoofs. All these creatures grew alertly on guard when the shadows lengthened and the long-drawn baying of the wolf pack heralded the night of slaughter and of fear; and the dusk thrilled with the ominous questing yawns of sabretooth and giant tiger, as the beasts of havoc prowled abroad from their day lairs among the manzanitas, or under cypress and live-oak.
The tar-pools caught birds as well as beasts. Most of these birds were modern--vultures, eagles, geese, herons. But there were condor-like birds twice the size of any living condor, the biggest birds, so far as we know, that ever flew. There were also, instead of wild turkeys, great quant.i.ties of wild peac.o.c.ks--at least they have been identified as peac.o.c.ks or similar big, pheasant-like birds. If the identification is correct, this is an unexpected discovery and a fresh proof of how this extinct American fauna at so many points resembled that of Asia. It was natural that a collateral ancestor of the present Asiatic pheasant-like birds should dwell beside a collateral ancestor of the present Asiatic tiger.[1]
Moreover, the tar-pools hold human bones. These, however, are probably of much later date than the magnificent fauna above described, perhaps only a few thousand years old. They belong to a rather advanced type of man. It is probable that before man came to America at all, the earlier types had died out in Eurasia, or had been absorbed and developed, or else had been thrust southward into Africa, Tasmania, Australia, and remote forest tracts of Indo-Malaysia, where, being such backward savages, they never developed anything remotely resembling a civilization. It was probably people kin to some of the later cave-dwellers who furnished the first (and perhaps until the advent of the white man the only important) immigration to America. These immigrants, the ancestors of all the tribes of Indians, spread from Alaska to Tierra del Fuego. Over most of the territory in both Americas they remained at the hunting stage of savage life, although they generally supplemented their hunting by a certain amount of cultivation of the soil, and although in places they developed into advanced and very peculiar culture communities.
When these savages reached North America it is likely, from our present knowledge, that the terrible and magnificent Pleistocene fauna had vanished, although in places the last survivors of the mastodon, and perhaps of one or two other forms, may still have lingered. What were the causes of this wide-spread, and complete, and--geologically speaking--sudden extermination of so many and so varied types of great herbivorous creatures, we cannot say. It may be we can never do more than guess at them. It is certainly an extraordinary thing that complete destruction should have suddenly fallen on all, literally all, of the species. Camels and horses, after they had dwelt on this continent for millions of years, since almost the dawn of mammalian life, developing from little beasts the size of woodchucks into the largest and most stately creatures of their kind that ever trod the earth"s surface, all at once disappeared to the very last individual. Ground-sloths and elephants vanished likewise. The bigger forms of bison also died out, although one species remained. Many causes of extinction have been suggested. Perhaps all of them were more or less operative. Perhaps others of which we know nothing were operative. We cannot say.
But as regards certain of the formidable, but heavy rather than active, beasts of prey it is possible to hazard a guess. Compared to agile destroyers like the cougar and the timber-wolf, the sabretooth and the big-headed, small-legged giant wolf were strong, heavy, rather clumsy creatures. Predatory animals of their kind were beasts of battle rather than beasts of the chase. They were fitted to overcome by downright fighting strength a big, slow, self-confident quarry, rather than to run down a swift and timid quarry by speed or creep up to a wary and timid quarry by sinuous stealth. So long as the heavy herbivores were the most numerous these fighting carnivores were dominant over their sly, swift, slinking brethren. But when the great ma.s.s of plant-eaters grew to trust to speed and vigilance for their safety there was no longer room for preying beasts of mere prowess.
In South America it is probable that the heavy fauna died out much later than in North America and northern Eurasia; that is, it died out much later than in what zoogeographers call the holarctic realm. During most of the Tertiary period or age of mammals, the period intervening between the close of the age of great reptiles and the time when man in human form appeared on the planet, South America was an island, and its faunal history was as distinct and peculiar as that of Australia. Aside from marsupials and New World monkeys, its most characteristic animals were edentates and very queer ungulates with no resemblance to those of any other continent. Toward the close of the Tertiary land bridges connected the two Americas, and an interchange of faunas followed. The South American fauna was immensely enriched by the incoming of elephants, horses, sabretooth cats, true cats, camels, bears, tapirs, peccaries, deer, and dogs, all of which developed along new and individual lines. A few of these species, llamas and tapirs for instance, still persist in South America although they have died out in the land from which they came. But in the end, and also for unknown causes, this great fauna died out in South America likewise, leaving a continent faunistically even more impoverished than North America. The great autochthonous forms shared the extinction of the big creatures of the immigrant fauna; for under stress of compet.i.tion with the newcomers, the ancient ungulates and edentates had developed giants of their own.
Recent discoveries have shown that the extinction was not complete when the ancestors of the Indians of to-day reached the southern Andes and the Argentine plains. An age previously the forefathers of these newcomers had lived in a land with the wild horse, the wild elephant, and the lion; and now, at the opposite end of the world, they had themselves reached such a land. The elephants were mastodons of peculiar type; the horses were of several kinds, some resembling modern horses, others differing from them in leg and skull formation more than any of the existing species of a.s.s, horse, or zebra differ from one another; the huge cats probably resembled some other big modern feline more than they did the lion. a.s.sociated with them were many great beasts, whose like does not now exist on earth. The sabretooth was there, as formidable as his brother of the north, and, like this brother, bigger and more specialized than any of his Old World kin, which were probably already extinct. Among the ungulates of native origin was the long-necked, high-standing macrauchenia, shaped something like a huge, humpless camel or giraffe, and with a short proboscis. This animal doubtless browsed among the trees. Another native ungulate, the toxodon, as big and heavily made as a rhinoceros, was probably amphibious, and had teeth superficially resembling those of a rodent. The edentates not only included various ground-sloths, among them the megatherium, which was the size of an elephant, and the somewhat smaller mylodon, but also creatures as fantastic as those of a nightmare. These were the glyptodons, which were bulkier than oxen and were clad in defensive plate-armor more complete than that of an armadillo; in one species the long, armored tail terminated in a huge spiked k.n.o.b, like that of some forms of mediaeval mace.
The glyptodons doubtless trusted for protection to their mailed coats.
The ground-sloths had no armor. Like the terrestrial ant-bear of Brazil they walked slowly on the outer edges of their fore feet, which were armed with long and powerful digging claws. They could neither flee nor hide; and it seems a marvel that they could have held their own in the land against the big cats and sabretooth. Yet they persisted for ages, and spread northward from South America. It is hard to account for this.
But it is just as hard to account for certain phenomena that are occurring before our very eyes. While journeying through the interior of Brazil I not infrequently came across the big tamandua, the ant-bear or ant-eater. We found it not only in the forests but out on the marshes and prairies. It is almost as big as a small black bear. In its native haunts it is very conspicuous, both because of its size and its coloration, and as it never attempts to hide it is always easily seen.
It is so slow that a man can run it down on foot. It has no teeth, and its long, curved snout gives its small head an almost bird-like look.
Its fore paws, armed with long, digging claws, are turned in, and it walks on their sides. It is long-haired and thick-hided, colored black and white, and with a long, bushy tail held aloft; and as it retreats at a wabbly canter, its brush shaking above its back, it looks anything but formidable. Yet it is a gallant fighter, and can inflict severe wounds with its claws, as well as hugging with its powerful fore legs; and if menaced it will itself fearlessly a.s.sail man or dog. When chased by hounds, in the open, I have seen one instantly throw itself on its back, in which position it was much more dangerous to the hounds than they were to it. Doubtless if attacked by a jaguar--and we killed jaguars in the immediate neighborhood--it would, if given a moment"s warning, have defended itself in the same fashion. I suppose that this defense would be successful; for otherwise it seems incredible that such a conspicuous, slow-moving beast can exist at all in exactly the places where jaguars, able to kill a cow or horse, are plentiful. But, even so, it is difficult to understand how it has been able to persist for ages in company with the great spotted cat, the tyrant of the Brazilian wilderness. At any rate, with this example before us, we need not wonder overmuch at the ability of megatherium and mylodon to hold their own in the presence of the sabretooth.