P693:3, 61:0.3 The accumulated deposits of the five periods of this fifty-million-year era contain the fossil records of the successive mammalian dynasties and lead right up through the times of the actual appearance of man himself.
P693:4, 61:1.1 50,000,000 years ago the land areas of
the world were very generally above water or only slightly submerged. The
formations and deposits of this period are both land and marine, but chiefly
land. For a considerable time the land gradually rose but was simultaneously
washed down to the lower levels and toward the seas
P693:5, 61:1.2 Early in this period and in North America the
placental type of mammals suddenly appeared, and they constituted the
most important evolutionary development up to this time. Previous orders of
non-placental mammals had existed, but this new type sprang directly and suddenly
from the pre-existent reptilian ancestor whose descendants had persisted on
down through the times of dinosaur decline. The father of the placental mammals
was a small, highly active, carnivorous, springing type of dinosaur.
P693:6, 61:1.3 Basic mammalian instincts began to be manifested
in these primitive mammalian types. Mammals possess an immense survival
advantage over all other forms of animal life in that they can:
P694:1, 61:1.4 45,000,000 years ago the continental backbones were elevated in association with a very general sinking of the coast lines. Mammalian life was evolving rapidly. A small reptilian, egg-laying type of mammal flourished, and the ancestors of the later kangaroos roamed Australia. Soon there were small horses, fleet- footed rhinoceroses, tapirs with proboscises, primitive pigs, squirrels, lemurs, opossums, and several tribes of monkeylike animals. They were all small, primitive, and best suited to living among the forests of the mountain regions. A large ostrich-like land bird developed to a height of ten feet and laid an egg nine by thirteen inches.
P694:2, 61:1.5 The mammals of the early Cenozoic lived on land, under the water, in the air, and among the treetops. They had from one to eleven pairs of mammary glands, and all were covered with considerable hair. In common with the later appearing orders, they developed two successive sets of teeth and possessed large brains in comparison to body size. But among them all no modern forms existed.
P694:3, 61:1.6 40,000,000 years ago the land areas of
the Northern Hemisphere began to elevate, and this was followed by new extensive
land deposits and other terrestrial activities, including lava flows, warping,
lake formation, and erosion.
P694:4, 61:1.7 During the latter part of this epoch most of
Europe was submerged. Following a slight land rise, lakes and bays covered the
continent. The Arctic Ocean, through the Ural depression, ran south to connect
with the Mediterranean Sea as it was then expanded northward, the highlands of
the Alps, Carpathians, Apennines, and Pyrenees being up above the water as
islands of the sea. The Isthmus of Panama was up; the Atlantic and Pacific
Oceans were separated. North America was connected with Asia by the Bering
Strait land bridge and with Europe by way of Greenland and Iceland. The earth
circuit of land in northern latitudes was broken only by the Ural Straits, which
connected the arctic seas with the enlarged Mediterranean.
P694:5, 61:1.8 Considerable foraminifera limestone was
deposited in European waters. Today this same stone is elevated to a height of
10,000 feet in the Alps, 16,000 feet in the Himalayas, and 20,000 feet in Tibet.
The chalk deposits of this period are found along the coasts of Africa and
Australia, on the west coast of South America, and about the West Indies.
P694:6, 61:1.9 Throughout this so-called Eocene period the evolution of mammalian and other related forms of life continued with little or no interruption. North America was then connected by land with every continent except Australia, and primitive mammalian fauna of various types gradually overran the world.
P694:7, 61:2.1 This period was characterized by the further and
rapid evolution of placental mammals, the more progressive forms of mammalian
life developing during these times.
P694:8, 61:2.2 Although the early placental mammals sprang from
carnivorous ancestors, very soon herbivorous branches developed, and, erelong,
omnivorous mammalian families also sprang up. The angiosperms were the principal
food of the rapidly increasing mammals, the modern land flora, including the
majority of present-day plants and trees, having appeared during earlier
periods.
P695:1, 61:2.3 35,000,000 years ago marks the beginning
of the age of placental-mammalian world domination. The southern land bridge was
extensive, reconnecting the then enormous Antarctic continent with South
America, South Africa, and Australia. In spite of the massing of land in high
latitudes, the world climate remained relatively mild because of the enormous
increase in the size of the tropic seas, nor was the land elevated sufficiently
to produce glaciers. Extensive lava flows occurred in Greenland and Iceland,
some coal being deposited between these layers.
P695:2, 61:2.4 Marked changes were taking place in the fauna of
the planet. The sea life was undergoing great modification; most of the
present-day orders of marine life were in existence, and foraminifers continued
to play an important role. The insect life was much like that of the previous
era. The Florissant fossil beds of Colorado belong to the later years of these
far-distant times. Most of the living insect families go back to this period,
but many then in existence are now extinct, though their fossils remain.
P695:3, 61:2.5 On land this was pre-eminently the age of
mammalian renovation and expansion. Of the earlier and more primitive mammals,
over one hundred species were extinct before this period ended. Even the mammals
of large size and small brain soon perished. Brains and agility had replaced
armor and size in the progress of animal survival. And with the dinosaur family
on the decline, the mammals slowly assumed domination of the earth, speedily and
completely destroying the remainder of their reptilian ancestors.
P695:4, 61:2.6 Along with the disappearance of the dinosaurs,
other and great changes occurred in the various branches of the saurian family.
The surviving members of the early reptilian families are turtles, snakes, and
crocodiles, together with the venerable frog, the only remaining group
representative of man's earlier ancestors.
P695:6, 61:2.8 30,000,000 years ago the modern types of
mammals began to make their appearance. Formerly the mammals had lived for the
greater part in the hills, being of the mountainous types; suddenly there
began the evolution of the plains or hoofed type, the grazing species, as
differentiated from the clawed flesh eaters. These grazers sprang from an
undifferentiated ancestor having five toes and forty-four teeth, which perished
before the end of the age. Toe evolution did not progress beyond the three-toed
stage throughout this period.
P695:7, 61:2.9 The horse, an outstanding example of evolution,
lived during these times in both North America and Europe, though his
development was not fully completed until the later ice age. While the
rhinoceros family appeared at the close of this period, it underwent its
greatest expansion subsequently. A small hog-like creature also developed which
became the ancestor of the many species of swine, peccaries, and hippopotamuses.
Camels and llamas had their origin in North America about the middle of this
period and overran the western plains. Later, the llamas migrated to South
America, the camels to Europe, and soon both were extinct in North America,
though a few camels survived up to the ice age.
P696:1, 61:2.10 About this time a notable thing occurred in
western North America: The early ancestors of the ancient lemurs first made
their appearance. While this family cannot be regarded as true lemurs, their
coming marked the establishment of the line from which the true lemurs
subsequently sprang.
P696:2, 61:2.11 Like the land serpents of a previous age which
betook themselves to the seas, now a whole tribe of placental mammals deserted
the land and took up their residence in the oceans. And they have ever since
remained in the sea, yielding the modern whales, dolphins, porpoises, seals, and
sea lions.
P696:3, 61:2.12 The bird life of the planet continued to
develop, but with few important evolutionary changes. The majority of modern
birds were existent, including gulls, herons, flamingoes, buzzards, falcons,
eagles, owls, quails, and ostriches.
P696:4, 61:2.13 By the close of this Oligocene period,
covering ten million years, the plant life, together with the marine life and
the land animals, had very largely evolved and was present on earth much as
today. Considerable specialization has subsequently appeared, but the ancestral
forms of most living things were then alive.
P696:5, 61:3.1 Land elevation and sea segregation were slowly
changing the world's weather, gradually cooling it, but the climate was still
mild. Sequoias and magnolias grew in Greenland, but the subtropical plants were
beginning to migrate southward. By the end of this period these warm-climate
plants and trees had largely disappeared from the northern latitudes, their
places being taken by more hardy plants and the deciduous trees.
P696:6, 61:3.2 There was a great increase in the varieties of
grasses, and the teeth of many mammalian species gradually altered to conform to
the present-day grazing type.
P696:7, 61:3.3 25,000,000 years ago there was a slight land submergence following the long epoch of land elevation. The Rocky Mountain region remained highly elevated so that the deposition of erosion material continued throughout the lowlands to the east. The Sierras were well re-elevated; in fact, they have been rising ever since. The great four-mile vertical fault in the California region dates from this time.
P696:8, 61:3.4 20,000,000 years ago was indeed the golden age of mammals. The Bering Strait land bridge was up, and many groups of animals migrated to North America from Asia, including the four-tusked mastodons, short- legged rhinoceroses, and many varieties of the cat family.
P696:9, 61:3.5 The first deer appeared, and North America was
soon overrun by ruminants -- deer, oxen, camels, bison, and several species of
rhinoceroses -- but the giant pigs, more than six feet tall, became extinct.
P697:1, 61:3.6 The huge elephants of this and subsequent
periods possessed large brains as well as large bodies, and they soon overran
the entire world except Australia. For once a huge animal with a brain
sufficiently large to enable it to carry on dominated the world. Confronted by
the highly intelligent life of these ages, no animal the size of an elephant
could have survived unless it had possessed a brain of large size and superior
quality. In intelligence and adaptation the elephant is approached only by the
horse and is surpassed only by man himself. Even so, of the fifty species of
elephants in existence at the opening of this period, only two have survived.
P697:2, 61:3.7 15,000,000 years ago the mountain regions
of Eurasia were rising, and there was some volcanic activity throughout these
regions, but nothing comparable to the lava flows of the Western Hemisphere.
These unsettled conditions prevailed all over the world.
P697:3, 61:3.8 The Strait of Gibraltar closed, and Spain was
connected with Africa by the old land bridge, but the Mediterranean flowed into
the Atlantic through a narrow channel which extended across France, the mountain
peaks and highlands appearing as islands above this ancient sea. Later on, these
European seas began to withdraw. Still later, the Mediterranean was connected
with the Indian Ocean, while at the close of this period the Suez region was
elevated so that the Mediterranean became, for a time, an inland salt sea.
P697:4, 61:3.9 The Iceland land bridge submerged, and the
arctic waters commingled with those of the Atlantic Ocean. The Atlantic coast of
North America rapidly cooled, but the Pacific coast remained warmer than at
present. The great ocean currents were in function and affected climate much as
they do today.
P697:5, 61:3.10 Mammalian life continued to evolve. Enormous
herds of horses joined the camels on the western plains of North America; this
was truly the age of horses as well as of elephants. The horse's brain is next
in animal quality to that of the elephant, but in one respect it is decidedly
inferior, for the horse never fully overcame the deep-seated propensity to flee
when frightened. The horse lacks the emotional control of the elephant, while
the elephant is greatly handicapped by size and lack of agility. During this
period an animal evolved which was somewhat like both the elephant and the
horse, but the rapidly increasing cat family soon destroyed it.
P697:6, 61:3.11 As Earth is entering the so-called "
horseless age," you should pause and ponder what this animal meant to your
ancestors. Men first used horses for food, then for travel, and later in
agriculture and war. The horse has long served mankind and has played an
important part in the development of human civilization.
P698:1, 61:3.14 Birds continued to evolve, though few marked changes occurred. Reptiles were similar to modern types -- snakes, crocodiles, and turtles.
P698:2, 61:3.15 Thus drew to a close a very eventful and interesting period of the world's history. This age of the elephant and the horse is known as the Miocene.
Part III. The History Of Earth
P698:4, 61:4.2 10,000,000 years ago began an age of
widespread local land deposits on the lowlands of the continents, but most of
these sedimentations were later removed. Much of Europe, at this time, was still
under water, including parts of England, Belgium, and France, and the
Mediterranean Sea covered much of northern Africa. In North America extensive
depositions were made at the mountain bases, in lakes, and in the great land
basins. These deposits average only about two hundred feet, are more or less
colored, and fossils are rare. Two great fresh-water lakes existed in western
North America. The Sierras were elevating; Shasta, Hood, and Rainier were
beginning their mountain careers. But it was not until the subsequent ice age
that North America began its creep toward the Atlantic depression.
P698:6, 61:4.4 In general, the life of the preceding period
continued to evolve and spread. The cat family dominated the animal life, and
marine life was almost at a standstill. Many of the horses were still
three-toed, but the modern types were arriving; llamas and giraffe-like camels
mingled with the horses on the grazing plains. The giraffe appeared in Africa,
having just as long a neck then as now. In South America sloth, armadillos,
anteaters, and the South American type of primitive monkeys evolved. Before the
continents were finally isolated, those massive animals, the mastodons, migrated
everywhere except to Australia.
P698:7, 61:4.5 5,000,000 years ago the horse evolved as
it now is and from North America migrated to all the world. But the horse had
become extinct on the continent of its origin long before the red man arrived.
P698:8, 61:4.6 The climate was gradually getting cooler; the
land plants were slowly moving southward. At first it was the increasing cold in
the north that stopped animal migrations over the northern isthmuses;
subsequently these North American land bridges went down. Soon afterwards the
land connection between Africa and South America finally submerged, and the
Western Hemisphere was isolated much as it is today. From this time forward
distinct types of life began to develop in the Eastern and Western Hemispheres.
P698:9, 61:4.7 And thus does this period of almost ten million years' duration draw to a close, and not yet has the ancestor of man appeared. This is the time usually designated as the Pliocene.
P699:1, 61:5.1 By the close of the preceding period the lands
of the northeastern part of North America and of northern Europe were highly
elevated on an extensive scale, in North America vast areas rising up to 30,000
feet and more. Mild climates had formerly prevailed over these northern regions,
and the arctic waters were all open to evaporation, and they continued to be
ice-free until almost the close of the glacial period.
P699:2, 61:5.2 Simultaneously with these land elevations the
ocean currents shifted, and the seasonal winds changed their direction. These
conditions eventually produced an almost constant precipitation of moisture from
the movement of the heavily saturated atmosphere over the northern highlands.
Snow began to fall on these elevated and therefore cool regions, and it
continued to fall until it had attained a depth of 20,000 feet. The areas of the
greatest depth of snow, together with altitude, determined the central points of
subsequent glacial pressure flows. And the ice age persisted just as long as
this excessive precipitation continued to cover these northern highlands with
this enormous mantle of snow, which soon metamorphosed into solid but creeping
ice.
P699:3, 61:5.3 The great ice sheets of this period were all
located on elevated highlands, not in mountainous regions where they are found
today. One half of the glacial ice was in North America, one fourth in Eurasia,
and one fourth elsewhere, chiefly in Antarctica. Africa was little affected by
the ice, but Australia was almost covered with the Antarctic ice blanket.
P699:4, 61:5.4 The northern regions of this world have
experienced six separate and distinct ice invasions, although there were scores
of advances and recessions associated with the activity of each individual ice
sheet. The ice in North America collected in two and, later, three centers.
Greenland was covered, and Iceland was completely buried beneath the ice flow.
In Europe the ice at various times covered the British Isles excepting the coast
of southern England, and it overspread Western Europe down to France.
P699:5, 61:5.5 2,000,000 years ago the first North American glacier started its southern advance. The ice age was now in the making, and this glacier consumed nearly one million years in its advance from, and retreat back toward, the northern pressure centers. The central ice sheet extended south as far as Kansas; the eastern and western ice centers were not then so extensive.
P699:6, 61:5.6 1,500,000 years ago the first great
glacier was retreating northward. In the meantime, enormous quantities of snow
had been falling on Greenland and on the northeastern part of North America, and
erelong this eastern ice mass began to flow southward. This was the second
invasion of the ice.
P699:7, 61:5.7 These first two ice invasions were not extensive
in Eurasia. During these early epochs of the ice age North America was overrun
with mastodons, woolly mammoths, horses, camels, deer, musk oxen, bison, ground
sloth, giant beavers, saber-toothed tigers, sloth as large as elephants, and
many groups of the cat and dog families. But from this time forward they were
rapidly reduced in numbers by the increasing cold of the glacial period. Toward
the close of the ice age the majority of these animal species were extinct in
North America.
P700:1, 61:5.8 Away from the ice the land and water life of the
world was little changed. Between the ice invasions the climate was about as
mild as at present, perhaps a little warmer. The glaciers were, after all, local
phenomena, though they spread out to cover enormous areas. The coastwise climate
varied greatly between the times of glacial inaction and those times when
enormous icebergs were sliding off the coast of Maine into the Atlantic,
slipping out through Puget Sound into the Pacific, and thundering down Norwegian
fiords into the North Sea.
P700:3, 61:6.2 1,000,000 years ago Earth was registered
as an inhabited world. A mutation within the stock of the progressing
Primates suddenly produced two primitive human beings, the actual
ancestors of mankind.
P700:4, 61:6.3 This event occurred at about the time of the
beginning of the third glacial advance; thus it may be seen that your early
ancestors were born and bred in a stimulating, invigorating, and difficult
environment. And the sole survivors of these Earth aborigines, the Eskimos, even
now prefer to dwell in frigid northern climes.
P700:5, 61:6.4 Human beings were not present in the Western Hemisphere until near the close of the ice age. But during the interglacial epochs they passed westward around the Mediterranean and soon overran the continent of Europe. In the caves of Western Europe may be found human bones mingled with the remains of both tropic and arctic animals, testifying that man lived in these regions throughout the later epochs of the advancing and retreating glaciers.
P701:1, 61:7.2 750,000 years ago the fourth ice sheet, a
union of the North American central and eastern ice fields, was well on its way
south; at its height it reached to southern Illinois, displacing the Mississippi
River fifty miles to the west, and in the east it extended as far south as the
Ohio River and central Pennsylvania.
P701:2, 61:7.3 In Asia the Siberian ice sheet made its
southernmost invasion, while in Europe the advancing ice stopped just short of
the mountain barrier of the Alps.
P701:3, 61:7.4 500,000 years ago, during the fifth advance of the ice, a new development accelerated the course of human evolution. Suddenly and in one generation, one race mutated from the aboriginal human stock.
P701:4, 61:7.5 In North America the advancing fifth glacier consisted of a combined invasion by all three ice centers. The eastern lobe, however, extended only a short distance below the St. Lawrence valley, and the western ice sheet made little southern advance. But the central lobe reached south to cover most of the State of Iowa. In Europe this invasion of the ice was not so extensive as the preceding one.
P701:5, 61:7.6 250,000 years ago the sixth and last
glaciation began. And despite the fact that the northern highlands had begun to
sink slightly, this was the period of greatest snow deposition on the northern
ice fields.
P701:6, 61:7.7 In this invasion the three great ice sheets
coalesced into one vast ice mass, and all of the western mountains participated
in this glacial activity. This was the largest of all ice invasions in North
America; the ice moved south over fifteen hundred miles from its pressure
centers, and North America experienced its lowest temperatures.
P701:8, 61:7.9 150,000 years ago the sixth and last
glacier reached its farthest points of southern extension, the western ice sheet
crossing just over the Canadian border; the central coming down into Kansas,
Missouri, and Illinois; the eastern sheet advancing south and covering the
greater portion of Pennsylvania and Ohio.
P701:9, 61:7.10 This is the glacier that sent forth the many
tongues, or ice lobes, which carved out the present-day lakes, great and small.
During its retreat the North American system of Great Lakes was produced. And
geologists have very accurately deduced the various stages of this development
and have correctly surmised that these bodies of water did, at different times,
empty first into the Mississippi valley, then eastward into the Hudson valley,
and finally by a northern route into the St. Lawrence. It is thirty-seven
thousand years since the connected Great Lakes system began to empty out over
the present Niagara route.
P702:1, 61:7.11 100,000 years ago, during the retreat of
the last glacier, the vast polar ice sheets began to form, and the center of ice
accumulation moved considerably northward. And as long as the Polar Regions
continue to be covered with ice, it is hardly possible for another glacial age
to occur, regardless of future land elevations or modification of ocean
currents.
P702:2, 61:7.12 This last glacier was one hundred thousand
years advancing, and it required a like span of time to complete its northern
retreat. The temperate regions have been free from the ice for a little over
fifty thousand years.
P702:3, 61:7.13 The rigorous glacial period destroyed many
species and radically changed numerous others. Many were sorely sifted by the
to-and-fro migration that was made necessary by the advancing and retreating
ice. Those animals that followed the glaciers back and forth over the land were
the bear, bison, reindeer, musk ox, mammoth, and mastodon.
P702:4, 61:7.14 The mammoth sought the open prairies, but the
mastodon preferred the sheltered fringes of the forest regions. The mammoth,
until a late date, ranged from Mexico to Canada; the Siberian variety became
wool covered. The mastodon persisted in North America until exterminated by the
red man much as the white man later killed off the bison.
P702:5, 61:7.15 In North America, during the last glaciation,
the horse, tapir, llama, and saber-toothed tiger became extinct. In their places
sloth, armadillos, and water hogs came up from South America.
P702:6, 61:7.16 The enforced migration of life before the
advancing ice led to an extraordinary commingling of plants and of animals, and
with the retreat of the final ice invasion, many arctic species of both plants
and animals were left stranded high upon certain mountain peaks, whither they
had journeyed to escape destruction by the glacier. And so, today, these
dislocated plants and animals may be found high up on the Alps of Europe and
even on the Appalachian Mountains of North America.
P702:7, 61:7.17 The ice age is the last completed geologic period, the so-called Pleistocene, over two million years in length.
P702:8, 61:7.18 35,000 years ago marks the termination of the great ice age excepting in the polar regions of the planet..
P702:9, 61:7.19 This narrative, extending from the rise of mammalian life to the retreat of the ice and on down to historic times, covers a span of almost fifty million years. This is the last -- the current -- geologic period and is known to your researchers as the Cenozoic or recent-times era.