The era of
mammals extends from the times of the origin of
placental mammals to the end of the ice age, covering a
little less than fifty million years.
Cenozoic age the world's landscape presented an
attractive appearance--rolling hills, broad valleys,
wide rivers, and great forests. Twice during this sector
of time the Panama Isthmus went up and down; three times
Bering Strait land bridge did the same. The animal types
were both many and varied. The trees swarmed with birds,
and the whole world was an animal paradise,
notwithstanding the incessant struggle of the evolving
animal species for supremacy.
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.
THE NEW CONTINENTAL LAND STAGE
THE AGE OF EARLY MAMMALS
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.
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 nonplacental 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.
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:
forth relatively mature and well-developed offspring.
Nourish, nurture, and protect their offspring with
their superior brain power in self-perpetuation.
Utilize increased agility in escaping from enemies.
superior intelligence to environmental adjustment and
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 ostrichlike land bird developed to a
height of ten feet and laid an egg nine by thirteen
inches. These were the ancestors of the later gigantic
passenger birds that were so highly intelligent, and
that onetime transported human beings through the air.
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.
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.
the latter part of this epoch most of Europe was
submerged. Following a slight land rise the continent
was covered by lakes and bays. 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
Considerable foraminiferal 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.
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 the world was gradually overrun by
primitive mammalian fauna of various types.
THE RECENT FLOOD STAGE
THE AGE OF ADVANCED MAMMALS
period was characterized by the further and rapid
evolution of placental mammals, the more progressive
forms of mammalian life developing during these times.
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.
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
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
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.
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.
groups of mammals had their origin in a unique animal
now extinct. This carnivorous creature was something of
a cross between a cat and a seal; it could live on land
or in water and was highly intelligent and very active.
In Europe the ancestor of the canine family evolved,
soon giving rise to many species of small dogs. About
the same time the gnawing rodents, including beavers,
squirrels, gophers, mice, and rabbits, appeared and soon
became a notable form of life, very little change having
since occurred in this family. The later deposits of
this period contain the fossil remains of dogs, cats,
coons, and weasels in ancestral form.
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
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 hoglike 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.
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
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.
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
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.
THE MODERN MOUNTAIN STAGE
THE AGE OF THE ELEPHANT AND THE HORSE
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.
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.
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.
20,000,000 years ago was indeed the golden age of
mammals. 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.
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.
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
the world was dominated by a huge animal with a brain
sufficiently large to enable it to carry on. 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
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.
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
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.
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 it
was soon destroyed by the rapidly increasing cat family.
Urantia 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.
biologic developments of this period contributed much
toward the setting of the stage for the subsequent
appearance of man. In central Asia the true types of
both the primitive monkey and the gorilla evolved,
having a common ancestor, now extinct. But neither of
these species is concerned in the line of living beings
which were, later on, to become the ancestors of the
family was represented by several groups, notably wolves
and foxes; the cat tribe, by panthers and large
saber-toothed tigers, the latter first evolving in North
America. The modern cat and dog families increased in
numbers all over the world. Weasels, martens, otters,
and raccoons thrived and developed throughout the
Birds continued to evolve, though few marked changes
occurred. Reptiles were similar to modern types--snakes,
crocodiles, and turtles.
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.
THE RECENT CONTINENTAL-ELEVATION STAGE
THE LAST GREAT MAMMALIAN MIGRATION
the period of preglacial land elevation in North
America, Europe, and Asia. The land was greatly altered
in topography. Mountain ranges were born, streams
changed their courses, and isolated volcanoes broke out
all over the world.
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.
short time all the land of the world was again joined
excepting Australia, and the last great world-wide
animal migration took place. North America was connected
with both South America and Asia, and there was a free
exchange of animal life. Asiatic sloths, armadillos,
antelopes, and bears entered North America, while North
American camels went to China. Rhinoceroses migrated
over the whole world except Australia and South America,
but they were extinct in the Western Hemisphere by the
close of this period.
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 giraffelike 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 sloths, 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.
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.
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.
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 EARLY ICE AGE
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.
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.
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.
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
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.
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.
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 sloths, giant
beavers, saber-toothed tigers, sloths 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.
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.
PRIMITIVE MAN IN THE ICE AGE
event of this glacial period was the evolution of
primitive man. Slightly to the west of India, on land
now under water and among the offspring of Asiatic
migrants of the older North American lemur types, the
dawn mammals suddenly appeared. These small
animals walked mostly on their hind legs, and they
possessed large brains in proportion to their size and
in comparison with the brains of other animals. In the
seventieth generation of this order of life a new and
higher group of animals suddenly differentiated.
These new mid-mammals--almost twice the size and height
of their ancestors and possessing proportionately
increased brain power--had only well established
themselves when the Primates, the third vital mutation,
suddenly appeared. (At this same time, a
retrograde development within the mid-mammal stock gave
origin to the simian ancestry; and from that day to this
the human branch has gone forward by progressive
evolution, while the simian tribes have remained
stationary or have actually retrogressed.)
1,000,000 years ago Urantia 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.
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 Urantia aborigines, the Eskimos, even
now prefer to dwell in frigid northern climes.
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
THE CONTINUING ICE AGE
Throughout the glacial period other activities were in
progress, but the action of the ice overshadows all
other phenomena in the northern latitudes. No other
terrestrial activity leaves such characteristic evidence
on the topography. The distinctive boulders and surface
cleavages, such as potholes, lakes, displaced stone, and
rock flour, are to be found in connection with no other
phenomenon in nature. The ice is also responsible for
those gentle swells, or surface undulations, known as
drumlins. And a glacier, as it advances, displaces
rivers and changes the whole face of the earth. Glaciers
alone leave behind them those telltale drifts--the
ground, lateral, and terminal moraines. These drifts,
particularly the ground moraines, extend from the
eastern seaboard north and westward in North America and
are found in Europe and Siberia.
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.
the Siberian ice sheet made its southernmost invasion,
while in Europe the advancing ice stopped just short of
the mountain barrier of the Alps.
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 the six
colored races mutated from the aboriginal human stock.
This is a doubly important date since it also marks the
arrival of the Planetary Prince.
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
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.
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
200,000 years ago, during the advance of the last
glacier, there occurred an episode which had much to do
with the march of events on Urantia--the Lucifer
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.
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 Urantian 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.
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.
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.
rigorous glacial period destroyed many species and
radically changed numerous others. Many were sorely
sifted by the to-and-fro migration which was made
necessary by the advancing and retreating ice. Those
animals which followed the glaciers back and forth over
the land were the bear, bison, reindeer, musk ox,
mammoth, and mastodon.
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
America, during the last glaciation, the horse, tapir,
llama, and saber-toothed tiger became extinct. In their
places sloths, armadillos, and water hogs came up from
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.
age is the last completed geologic period, the so-called
Pleistocene, over two million years in length.
years ago marks the termination of the great ice age
excepting in the polar regions of the planet. This date
is also significant in that it approximates the arrival
of a Material Son and Daughter and the beginning of the
Adamic dispensation, roughly corresponding to the
beginning of the Holocene or postglacial period.
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.
by a Resident Life Carrier.]