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The 5th Epochal Revelation
-The Urantia Papers
PAPER 59
THE MARINE-LIFE ERA ON URANTIA
59:0.1
WE RECKON the history of Urantia as beginning about one
billion years ago and extending through five major eras:
59:0.2
1. The prelife
era extends over the initial four hundred and fifty
million years, from about the time the planet attained
its present size to the time of life establishment. Your
students have designated this period as the
Archeozoic.
59:0.3
2. The life-dawn
era extends over the next one hundred and fifty
million years. This epoch intervenes between the
preceding prelife or cataclysmic age and the following
period of more highly developed marine life. This era is
known to your researchers as the
Proterozoic.
59:0.4
3. The
marine-life era covers the next two hundred and
fifty million years and is best known to you as the
Paleozoic.
59:0.5
4. The early
land-life era extends over the next one hundred
million years and is known as the
Mesozoic.
59:0.6
5. The mammalian
era occupies the last fifty million years. This
recent-times era is known as the
Cenozoic.
59:0.7
The marine-life era thus covers about one quarter of
your planetary history. It may be subdivided into six
long periods, each characterized by certain well-defined
developments in both the geologic realms and the
biologic domains.
59:0.8
As this era begins, the sea bottoms, the extensive
continental shelves, and the numerous shallow near-shore
basins are covered with prolific vegetation. The more
simple and primitive forms of animal life have already
developed from preceding vegetable organisms, and the
early animal organisms have gradually made their way
along the extensive coast lines of the various land
masses until the many inland seas are teeming with
primitive marine life. Since so few of these early
organisms had shells, not many have been preserved as
fossils. Nevertheless the stage is set for the opening
chapters of that great "stone book" of the life-record
preservation which was so methodically laid down during
the succeeding ages.
59:0.9
The continent of North America is wonderfully rich in
the fossil-bearing deposits of the entire marine-life
era. The very first and oldest layers are separated from
the later strata of the preceding period by extensive
erosion deposits which clearly segregate these two
stages of planetary development.
1. EARLY MARINE LIFE IN THE SHALLOW SEAS
THE TRILOBITE AGE
59:1.1
By the dawn of this period of relative quiet on the
earth's surface, life is confined to the various inland
seas and the oceanic shore line; as yet no form of land
organism has evolved. Primitive marine animals are well
established and are prepared for the next evolutionary
development. Ameba are typical survivors of this initial
stage of animal life, having made their appearance
toward the close of the preceding transition period.
59:1.2
400,000,000
years ago marine life, both vegetable and animal, is
fairly well distributed over the whole world. The world
climate grows slightly warmer and becomes more equable.
There is a general inundation of the seashores of the
various continents, particularly of North and South
America. New oceans appear, and the older bodies of
water are greatly enlarged.
59:1.3
Vegetation now for the first time crawls out upon the
land and soon makes considerable progress in adaptation
to a nonmarine habitat.
59:1.4
Suddenly and
without gradation ancestry the first multicellular
animals make their appearance. The trilobites have
evolved, and for ages they dominate the seas. From the
standpoint of marine life this is the trilobite age.
59:1.5
In the later portion of this time segment much of North
America and Europe emerged from the sea. The crust of
the earth was temporarily stabilized; mountains, or
rather high elevations of land, rose along the Atlantic
and Pacific coasts, over the West Indies, and in
southern Europe. The entire Caribbean region was highly
elevated.
59:1.6
390,000,000
years ago the land was still elevated. Over parts of
eastern and western America and western Europe may be
found the stone strata laid down during these times, and
these are the oldest rocks which contain trilobite
fossils. There were many long fingerlike gulfs
projecting into the land masses in which were deposited
these fossil-bearing rocks.
59:1.7
Within a few million years the Pacific Ocean began to
invade the American continents. The sinking of the land
was principally due to crustal adjustment, although the
lateral land spread, or continental creep, was also a
factor.
59:1.8
380,000,000
years ago Asia was subsiding, and all other continents
were experiencing a short-lived emergence. But as this
epoch progressed, the newly appearing Atlantic Ocean
made extensive inroads on all adjacent coast lines. The
northern Atlantic or Arctic seas were then connected
with the southern Gulf waters. When this southern sea
entered the Appalachian trough, its waves broke upon the
east against mountains as high as the Alps, but in
general the continents were uninteresting lowlands,
utterly devoid of scenic beauty.
59:1.9
The sedimentary deposits of these ages are of four
sorts:
1. Conglomerates -- matter deposited near the shore
lines.
2. Sandstones -- deposits made in shallow water but
where the waves were sufficient to prevent mud settling.
3. Shales -- deposits made in the deeper and more quiet
water.
4. Limestone -- including the deposits of trilobite
shells in deep water.
59:1.10
The trilobite fossils of these times present certain
basic uniformities coupled with certain well-marked
variations. The early animals developing from the three
original life implantations were characteristic; those
appearing in the Western Hemisphere were slightly
different from those of the Eurasian group and from the
Australasian or Australian-Antarctic type.
59:1.11
370,000,000
years ago the great and almost total submergence of
North and South America occurred, followed by the
sinking of Africa and Australia. Only certain parts of
North America remained above these shallow Cambrian
seas. Five million years later the seas were retreating
before the rising land. And all of these phenomena of
land sinking and land rising were undramatic, taking
place slowly over millions of years.
59:1.12
The trilobite fossil-bearing strata of this epoch
outcrop here and there throughout all the continents
except in central Asia. In many regions these rocks are
horizontal, but in the mountains they are tilted and
distorted because of pressure and folding. And such
pressure has, in many places, changed the original
character of these deposits. Sandstone has been turned
into quartz, shale has been changed to slate, while
limestone has been converted into marble.
59:1.13
360,000,000
years ago the land was still rising. North and South
America were well up. Western Europe and the British
Isles were emerging, except parts of Wales, which were
deeply submerged. There were no great ice sheets during
these ages. The supposed glacial deposits appearing in
connection with these strata in Europe, Africa, China,
and Australia are due to isolated mountain glaciers or
to the displacement of glacial debris of later origin.
The world climate was oceanic, not continental. The
southern seas were warmer then than now, and they
extended northward over North America up to the polar
regions. The Gulf Stream coursed over the central
portion of North America, being deflected eastward to
bathe and warm the shores of Greenland, making that now
ice-mantled continent a veritable tropic Paradise.
59:1.14
The marine life was much alike the world over and
consisted of the seaweeds, one-celled organisms, simple
sponges, trilobites, and other crustaceans -- shrimps,
crabs, and lobsters. Three thousand varieties of
brachiopods appeared at the close of this period, only
two hundred of which have survived. These animals
represent a variety of early life which has come down to
the present time practically unchanged.
59:1.15
But the trilobites were the dominant living creatures.
They were sexed animals and existed in many forms; being
poor swimmers, they sluggishly floated in the water or
crawled along the sea bottoms, curling up in
self-protection when attacked by their later appearing
enemies. They grew in length from two inches to one foot
and developed into four distinct groups: carnivorous,
herbivorous, omnivorous, and "mud eaters." The ability
of the latter group largely to subsist on inorganic
matter -- being the last multicelled animal that could
-- explains their great increase and long survival.
59:1.16
This was the biogeologic picture of Urantia at the end
of that long period of the world's history, embracing
fifty million years, designated by your geologists as
the Cambrian.
2. THE FIRST CONTINENTAL FLOOD STAGE
THE INVERTEBRATE-ANIMAL AGE
59:2.1
The periodic phenomena of land elevation and land
sinking characteristic of these times were all gradual
and nonspectacular, being accompanied by little or no
volcanic action. Throughout all of these successive land
elevations and depressions the Asiatic mother continent
did not fully share the history of the other land
bodies. It experienced many inundations, dipping first
in one direction and then another, more particularly in
its earlier history, but it does not present the uniform
rock deposits which may be discovered on the other
continents. In recent ages Asia has been the most stable
of all the land masses.
59:2.2
350,000,000
years ago saw the beginning of the great flood period of
all the continents except central Asia. The land masses
were repeatedly covered with water; only the coastal
highlands remained above these shallow but widespread
oscillatory inland seas. Three major inundations
characterized this period, but before it ended, the
continents again arose, the total land emergence being
fifteen per cent greater than now exists. The Caribbean
region was highly elevated. This period is not well
marked off in Europe because the land fluctuations were
less, while the volcanic action was more persistent.
59:2.3
340,000,000
years ago there occurred another extensive land sinking
except in Asia and Australia. The waters of the world's
oceans were generally commingled. This was a great
limestone age, much of its stone being laid down by
lime-secreting algae.
59:2.4
A few million years later large portions of the American
continents and Europe began to emerge from the water. In
the Western Hemisphere only an arm of the Pacific Ocean
remained over Mexico and the present Rocky Mountain
regions, but near the close of this epoch the Atlantic
and Pacific coasts again began to sink.
59:2.5
330,000,000
years ago marks the beginning of a time sector of
comparative quiet all over the world, with much land
again above water. The only exception to this reign of
terrestrial quiet was the eruption of the great North
American volcano of eastern Kentucky, one of the
greatest single volcanic activities the world has ever
known. The ashes of this volcano covered five hundred
square miles to a depth of from fifteen to twenty feet.
59:2.6
320,000,000
years ago the third major flood of this period occurred.
The waters of this inundation covered all the land
submerged by the preceding deluge, while extending
farther in many directions all over the Americas and
Europe. Eastern North America and western Europe were
from 10,000 to 15,000 feet under water.
59:2.7
310,000,000
years ago the land masses of the world were again well
up excepting the southern parts of North America. Mexico
emerged, thus creating the Gulf Sea, which has ever
since maintained its identity.
59:2.8
The life of this period continues to evolve. The world
is once again quiet and relatively peaceful; the climate
remains mild and equable; the land plants are migrating
farther and farther from the seashores. The life
patterns are well developed, although few plant fossils
of these times are to be found.
59:2.9
This was the great age of individual animal organismal
evolution, though many of the basic changes, such as the
transition from plant to animal, had previously
occurred. The marine fauna developed to the point where
every type of life below the vertebrate scale was
represented in the fossils of those rocks which were
laid down during these times. But all of these animals
were marine organisms. No land animals had yet appeared
except a few types of worms which burrowed along the
seashores, nor had the land plants yet overspread the
continents; there was still too much carbon dioxide in
the air to permit of the existence of air breathers.
Primarily, all animals except certain of the more
primitive ones are directly or indirectly dependent on
plant life for their existence.
59:2.10
The trilobites were still prominent. These little
animals existed in tens of thousands of patterns and
were the predecessors of modern crustaceans. Some of the
trilobites had from twenty-five to four thousand tiny
eyelets; others had aborted eyes. As this period closed,
the trilobites shared domination of the seas with
several other forms of invertebrate life. But they
utterly perished during the beginning of the next
period.
59:2.11
Lime-secreting algae were widespread. There existed
thousands of species of the early ancestors of the
corals. Sea worms were abundant, and there were many
varieties of jellyfish which have since become extinct.
Corals and the later types of sponges evolved. The
cephalopods were well developed, and they have survived
as the modern pearly nautilus, octopus, cuttlefish, and
squid.
59:2.12
There were many varieties of shell animals, but their
shells were not then so much needed for defensive
purposes as in subsequent ages. The gastropods were
present in the waters of the ancient seas, and they
included single-shelled drills, periwinkles, and snails.
The bivalve gastropods have come on down through the
intervening millions of years much as they then existed
and embrace the muscles, clams, oysters, and scallops.
The valve-shelled organisms also evolved, and these
brachiopods lived in those ancient waters much as they
exist today; they even had hinged, notched, and other
sorts of protective arrangements of their valves.
59:2.13
So ends the evolutionary story of the second great
period of marine life, which is known to your geologists
as the Ordovician.
3. THE SECOND GREAT FLOOD STAGE
THE CORAL PERIOD -- THE BRACHIOPOD AGE
59:3.1
300,000,000
years ago another great period of land submergence
began. The southward and northward encroachment of the
ancient Silurian seas made ready to engulf most of
Europe and North America. The land was not elevated far
above the sea so that not much deposition occurred about
the shore lines. The seas teemed with lime-shelled life,
and the falling of these shells to the sea bottom
gradually built up very thick layers of limestone. This
is the first widespread limestone deposit, and it covers
practically all of Europe and North America but only
appears at the earth's surface in a few places. The
thickness of this ancient rock layer averages about one
thousand feet, but many of these deposits have since
been greatly deformed by tilting, upheavals, and
faulting, and many have been changed to quartz, shale,
and marble.
59:3.2
No fire rocks or lava are found in the stone layers of
this period except those of the great volcanoes of
southern Europe and eastern Maine and the lava flows of
Quebec. Volcanic action was largely past. This was the
height of great water deposition; there was little or no
mountain building.
59:3.3
290,000,000
years ago the sea had largely withdrawn from the
continents, and the bottoms of the surrounding oceans
were sinking. The land masses were little changed until
they were again submerged. The early mountain movements
of all the continents were beginning, and the greatest
of these crustal upheavals were the Himalayas of Asia
and the great Caledonian Mountains, extending from
Ireland through Scotland and on to Spitzbergen.
59:3.4
It is in the deposits of this age that much of the gas,
oil, zinc, and lead are found, the gas and oil being
derived from the enormous collections of vegetable and
animal matter carried down at the time of the previous
land submergence, while the mineral deposits represent
the sedimentation of sluggish bodies of water. Many of
the rock salt deposits belong to this period.
59:3.5
The trilobites rapidly declined, and the center of the
stage was occupied by the larger mollusks, or
cephalopods. These animals grew to be fifteen feet long
and one foot in diameter and became masters of the seas.
This species of animal appeared
suddenly and
assumed dominance of sea life.
59:3.6
The great volcanic activity of this age was in the
European sector. Not in millions upon millions of years
had such violent and extensive volcanic eruptions
occurred as now took place around the Mediterranean
trough and especially in the neighborhood of the British
Isles. This lava flow over the British Isles region
today appears as alternate layers of lava and rock
25,000 feet thick. These rocks were laid down by the
intermittent lava flows which spread out over a shallow
sea bed, thus interspersing the rock deposits, and all
of this was subsequently elevated high above the sea.
Violent earthquakes took place in northern Europe,
notably in Scotland.
59:3.7
The oceanic climate remained mild and uniform, and the
warm seas bathed the shores of the polar lands.
Brachiopod and other marine-life fossils may be found in
these deposits right up to the North Pole. Gastropods,
brachiopods, sponges, and reef-making corals continued
to increase.
59:3.8
The close of this epoch witnesses the second advance of
the Silurian seas with another commingling of the waters
of the southern and northern oceans. The cephalopods
dominate marine life, while associated forms of life
progressively develop and differentiate.
59:3.9
280,000,000
years ago the continents had largely emerged from the
second Silurian inundation. The rock deposits of this
submergence are known in North America as Niagara
limestone because this is the stratum of rock over which
Niagara Falls now flows. This layer of rock extends from
the eastern mountains to the Mississippi valley region
but not farther west except to the south. Several layers
extend over Canada, portions of South America,
Australia, and most of Europe, the average thickness of
this Niagara series being about six hundred feet.
Immediately overlying the Niagara deposit, in many
regions may be found a collection of conglomerate,
shale, and rock salt. This is the accumulation of
secondary subsidences. This salt settled in great
lagoons which were alternately opened up to the sea and
then cut off so that evaporation occurred with
deposition of salt along with other matter held in
solution. In some regions these rock salt beds are
seventy feet thick.
59:3.10
The climate is even and mild, and marine fossils are
laid down in the arctic regions. But by the end of this
epoch the seas are so excessively salty that little life
survives.
59:3.11
Toward the close of the final Silurian submergence there
is a great increase in the echinoderms -- the stone
lilies -- as is evidenced by the crinoid limestone
deposits. The trilobites have nearly disappeared, and
the mollusks continue monarchs of the seas; coral-reef
formation increases greatly. During this age, in the
more favorable locations the primitive water scorpions
first evolve. Soon thereafter, and
suddenly, the
true scorpions -- actual air breathers -- make their
appearance.
59:3.12
These developments terminate the third marine-life
period, covering twenty-five million years and known to
your researchers as the Silurian.
4. THE GREAT LAND-EMERGENCE STAGE
THE VEGETATIVE LAND-LIFE PERIOD
THE AGE OF FISHES
59:4.1
In the agelong struggle between land and water, for long
periods the sea has been comparatively victorious, but
times of land victory are just ahead. And the
continental drifts have not proceeded so far but that,
at times, practically all of the land of the world is
connected by slender isthmuses and narrow land bridges.
59:4.2
As the land emerges from the last Silurian inundation,
an important period in world development and life
evolution comes to an end. It is the dawn of a new age
on earth. The naked and unattractive landscape of former
times is becoming clothed with luxuriant verdure, and
the first magnificent forests will soon appear.
59:4.3
The marine life of this age was very diverse due to the
early species segregation, but later on there was free
commingling and association of all these different
types. The brachiopods early reached their climax, being
succeeded by the arthropods, and barnacles made their
first appearance. But the greatest event of all was the
sudden appearance of the fish family. This became the
age of fishes, that period of the world's history
characterized by the
vertebrate
type of animal.
59:4.4
270,000,000
years ago the continents were all above water. In
millions upon millions of years not so much land had
been above water at one time; it was one of the greatest
land-emergence epochs in all world history.
59:4.5
Five million years later the land areas of North and
South America, Europe, Africa, northern Asia, and
Australia were briefly inundated, in North America the
submergence at one time or another being almost
complete; and the resulting limestone layers run from
500 to 5,000 feet in thickness. These various Devonian
seas extended first in one direction and then in another
so that the immense arctic North American inland sea
found an outlet to the Pacific Ocean through northern
California.
59:4.6
260,000,000
years ago, toward the end of this land-depression epoch,
North America was partially overspread by seas having
simultaneous connection with the Pacific, Atlantic,
Arctic, and Gulf waters. The deposits of these later
stages of the first Devonian flood average about one
thousand feet in thickness. The coral reefs
characterizing these times indicate that the inland seas
were clear and shallow. Such coral deposits are exposed
in the banks of the Ohio River near Louisville,
Kentucky, and are about one hundred feet thick,
embracing more than two hundred varieties. These coral
formations extend through Canada and northern Europe to
the arctic regions.
59:4.7
Following these submergences, many of the shore lines
were considerably elevated so that the earlier deposits
were covered by mud or shale. There is also a red
sandstone stratum which characterizes one of the
Devonian sedimentations, and this red layer extends over
much of the earth's surface, being found in North and
South America, Europe, Russia, China, Africa, and
Australia. Such red deposits are suggestive of arid or
semiarid conditions, but the climate of this epoch was
still mild and even.
59:4.8
Throughout all of this period the land southeast of the
Cincinnati Island remained well above water. But very
much of western Europe, including the British Isles, was
submerged. In Wales, Germany, and other places in Europe
the Devonian rocks are 20,000 feet thick.
59:4.9
250,000,000
years ago witnessed the appearance of the fish family,
the vertebrates, one of the most important steps in all
prehuman evolution.
59:4.10
The arthropods, or crustaceans, were the ancestors of
the first vertebrates. The forerunners of the fish
family were two modified arthropod ancestors; one had a
long body connecting a head and tail, while the other
was a backboneless, jawless prefish. But these
preliminary types were quickly destroyed when the
fishes, the first vertebrates of the animal world, made
their sudden
appearance from the north.
59:4.11
Many of the largest true fish belong to this age, some
of the teeth-bearing varieties being twenty-five to
thirty feet long; the present-day sharks are the
survivors of these ancient fishes. The lung and armored
fishes reached their evolutionary apex, and before this
epoch had ended, fishes had adapted to both fresh and
salt waters.
59:4.12
Veritable bone beds of fish teeth and skeletons may be
found in the deposits laid down toward the close of this
period, and rich fossil beds are situated along the
coast of California since many sheltered bays of the
Pacific Ocean extended into the land of that region.
59:4.13
The earth was being rapidly overrun by the new orders of
land vegetation. Heretofore few plants grew on land
except about the water's edge. Now, and
suddenly, the
prolific fern
family appeared and quickly spread over the face of
the rapidly rising land in all parts of the world. Tree
types, two feet thick and forty feet high, soon
developed; later on, leaves evolved, but these early
varieties had only rudimentary foliage. There were many
smaller plants, but their fossils are not found since
they were usually destroyed by the still earlier
appearing bacteria.
59:4.14
As the land rose, North America became connected with
Europe by land bridges extending to Greenland. And today
Greenland holds the remains of these early land plants
beneath its mantle of ice.
59:4.15
240,000,000
years ago the land over parts of both Europe and North
and South America began to sink. This subsidence marked
the appearance of the last and least extensive of the
Devonian floods. The arctic seas again moved southward
over much of North America, the Atlantic inundated a
large part of Europe and western Asia, while the
southern Pacific covered most of India. This inundation
was slow in appearing and equally slow in retreating.
The Catskill Mountains along the west bank of the Hudson
River are one of the largest geologic monuments of this
epoch to be found on the surface of North America.
59:4.16
230,000,000
years ago the seas were continuing their retreat. Much
of North America was above water, and great volcanic
activity occurred in the St. Lawrence region. Mount
Royal, at Montreal, is the eroded neck of one of these
volcanoes. The deposits of this entire epoch are well
shown in the Appalachian Mountains of North America
where the Susquehanna River has cut a valley exposing
these successive layers, which attained a thickness of
over 13,000 feet.
59:4.17
The elevation of the continents proceeded, and the
atmosphere was becoming enriched with oxygen. The earth
was overspread by vast forests of ferns one hundred feet
high and by the peculiar trees of those days, silent
forests; not a sound was heard, not even the rustle of a
leaf, for such trees had no leaves.
59:4.18
And thus drew to a close one of the longest periods of
marine-life evolution,
the age of fishes.
This period of the world's history lasted almost fifty
million years; it has become known to your researchers
as the Devonian.
5. THE CRUSTAL-SHIFTING STAGE
THE FERN-FOREST CARBONIFEROUS PERIOD
THE AGE OF FROGS
59:5.1
The appearance of fish during the preceding period marks
the apex of marine-life evolution. From this point
onward the evolution of land life becomes increasingly
important. And this period opens with the stage almost
ideally set for the appearance of the first land
animals.
59:5.2
220,000,000
years ago many of the continental land areas, including
most of North America, were above water. The land was
overrun by luxurious vegetation; this was indeed the
age of ferns.
Carbon dioxide was still present in the atmosphere but
in lessening degree.
59:5.3
Shortly thereafter the central portion of North America
was inundated, creating two great inland seas. Both the
Atlantic and Pacific coastal highlands were situated
just beyond the present shore lines. These two seas
presently united, commingling their different forms of
life, and the union of these marine fauna marked the
beginning of the rapid and world-wide decline in marine
life and the opening of the subsequent land-life period.
59:5.4
210,000,000
years ago the warm-water arctic seas covered most of
North America and Europe. The south polar waters
inundated South America and Australia, while both Africa
and Asia were highly elevated.
59:5.5
When the seas were at their height, a new evolutionary
development
suddenly occurred. Abruptly, the first of the land
animals appeared. There were numerous species of these
animals that were able to live on land or in water.
These air-breathing amphibians developed from the
arthropods, whose swim bladders had evolved into lungs.
59:5.6
From the briny waters of the seas there crawled out upon
the land snails, scorpions, and frogs. Today frogs still
lay their eggs in water, and their young first exist as
little fishes, tadpoles. This period could well be known
as the age of
frogs.
59:5.7
Very soon thereafter the insects first appeared and,
together with spiders, scorpions, cockroaches, crickets,
and locusts, soon overspread the continents of the
world. Dragon flies measured thirty inches across. One
thousand species of cockroaches developed, and some grew
to be four inches long.
59:5.8
Two groups of echinoderms became especially well
developed, and they are in reality the guide fossils of
this epoch. The large shell-feeding sharks were also
highly evolved, and for more than five million years
they dominated the oceans. The climate was still mild
and equable; the marine life was little changed.
Fresh-water fish were developing and the trilobites were
nearing extinction. Corals were scarce, and much of the
limestone was being made by the crinoids. The finer
building limestones were laid down during this epoch.
59:5.9
The waters of many of the inland seas were so heavily
charged with lime and other minerals as greatly to
interfere with the progress and development of many
marine species. Eventually the seas cleared up as the
result of an extensive stone deposit, in some places
containing zinc and lead.
59:5.10
The deposits of this early Carboniferous age are from
500 to 2,000 feet thick, consisting of sandstone, shale,
and limestone. The oldest strata yield the fossils of
both land and marine animals and plants, along with much
gravel and basin sediments. Little workable coal is
found in these older strata. These depositions
throughout Europe are very similar to those laid down
over North America.
59:5.11
Toward the close of this epoch the land of North America
began to rise. There was a short interruption, and the
sea returned to cover about half of its previous beds.
This was a short inundation, and most of the land was
soon well above water. South America was still connected
with Europe by way of Africa.
59:5.12
This epoch witnessed the beginning of the Vosges, Black
Forest, and Ural mountains. Stumps of other and older
mountains are to be found all over Great Britain and
Europe.
59:5.13
200,000,000
years ago the really active stages of the Carboniferous
period began. For twenty million years prior to this
time the earlier coal deposits were being laid down, but
now the more extensive coal-formation activities were in
process. The length of the actual coal-deposition epoch
was a little over twenty-five million years.
59:5.14
The land was periodically going up and down due to the
shifting sea level occasioned by activities on the ocean
bottoms. This crustal uneasiness -- the settling and
rising of the land -- in connection with the prolific
vegetation of the coastal swamps, contributed to the
production of extensive coal deposits, which have caused
this period to be known as the
Carboniferous.
And the climate was still mild the world over.
59:5.15
The coal layers alternate with shale, stone, and
conglomerate. These coal beds over central and eastern
United States vary in thickness from forty to fifty
feet. But many of these deposits were washed away during
subsequent land elevations. In some parts of North
America and Europe the coal-bearing strata are 18,000
feet in thickness.
59:5.16
The presence of roots of trees as they grew in the clay
underlying the present coal beds demonstrates that coal
was formed exactly where it is now found. Coal is the
water-preserved and pressure-modified remains of the
rank vegetation growing in the bogs and on the swamp
shores of this faraway age. Coal layers often hold both
gas and oil. Peat beds, the remains of past vegetable
growth, would be converted into a type of coal if
subjected to proper pressure and heat. Anthracite has
been subjected to more pressure and heat than other
coal.
59:5.17
In North America the layers of coal in the various beds,
which indicate the number of times the land fell and
rose, vary from ten in Illinois, twenty in Pennsylvania,
thirty-five in Alabama, to seventy-five in Canada. Both
fresh- and salt-water fossils are found in the coal
beds.
59:5.18
Throughout this epoch the mountains of North and South
America were active, both the Andes and the southern
ancestral Rocky Mountains rising. The great Atlantic and
Pacific high coastal regions began to sink, eventually
becoming so eroded and submerged that the coast lines of
both oceans withdrew to approximately their present
positions. The deposits of this inundation average about
one thousand feet in thickness.
59:5.19
190,000,000
years ago witnessed a westward extension of the North
American Carboniferous sea over the present Rocky
Mountain region, with an outlet to the Pacific Ocean
through northern California. Coal continued to be laid
down throughout the Americas and Europe, layer upon
layer, as the coastlands rose and fell during these ages
of seashore oscillations.
59:5.20
180,000,000
years ago brought the close of the Carboniferous period,
during which coal had been formed all over the world --
in Europe, India, China, North Africa, and the Americas.
At the close of the coal-formation period North America
east of the Mississippi valley rose, and most of this
section has ever since remained above the sea. This
land-elevation period marks the beginning of the modern
mountains of North America, both in the Appalachian
regions and in the west. Volcanoes were active in Alaska
and California and in the mountain-forming regions of
Europe and Asia. Eastern America and western Europe were
connected by the continent of Greenland.
59:5.21
Land elevation began to modify the marine climate of the
preceding ages and to substitute therefor the beginnings
of the less mild and more variable continental climate.
59:5.22
The plants of these times were spore bearing, and the
wind was able to spread them far and wide. The trunks of
the Carboniferous trees were commonly seven feet in
diameter and often one hundred and twenty-five feet
high. The modern ferns are truly relics of these bygone
ages.
59:5.23
In general, these were the epochs of development for
fresh-water organisms; little change occurred in the
previous marine life. But the important characteristic
of this period was the
sudden
appearance of the frogs and their many cousins. The life
features of the coal age were
ferns and
frogs.
6. THE CLIMATIC TRANSITION STAGE
THE SEED-PLANT PERIOD
THE AGE OF BIOLOGIC TRIBULATION
59:6.1
This period marks the end of pivotal evolutionary
development in marine life and the opening of the
transition period leading to the subsequent ages of land
animals.
59:6.2
This age was one of great life impoverishment. Thousands
of marine species perished, and life was hardly yet
established on land. This was a time of biologic
tribulation, the age when life nearly vanished from the
face of the earth and from the depths of the oceans.
Toward the close of the long marine-life era there were
more than one hundred thousand species of living things
on earth. At the close of this period of transition less
than five hundred had survived.
59:6.3
The peculiarities of this new period were not due so
much to the cooling of the earth's crust or to the long
absence of volcanic action as to an unusual combination
of commonplace and pre-existing influences --
restrictions of the seas and increasing elevation of
enormous land masses. The mild marine climate of former
times was disappearing, and the harsher continental type
of weather was fast developing.
59:6.4
170,000,000
years ago great evolutionary changes and adjustments
were taking place over the entire face of the earth.
Land was rising all over the world as the ocean beds
were sinking. Isolated mountain ridges appeared. The
eastern part of North America was high above the sea;
the west was slowly rising. The continents were covered
by great and small salt lakes and numerous inland seas
which were connected with the oceans by narrow straits.
The strata of this transition period vary in thickness
from 1,000 to 7,000 feet.
59:6.5
The earth's crust folded extensively during these land
elevations. This was a time of continental emergence
except for the disappearance of certain land bridges,
including the continents which had so long connected
South America with Africa and North America with Europe.
59:6.6
Gradually the inland lakes and seas were drying up all
over the world. Isolated mountain and regional glaciers
began to appear, especially over the Southern
Hemisphere, and in many regions the glacial deposit of
these local ice formations may be found even among some
of the upper and later coal deposits. Two new climatic
factors appeared -- glaciation and aridity. Many of the
earth's higher regions had become arid and barren.
59:6.7
Throughout these times of climatic change, great
variations also occurred in the land plants. The
seed plants
first appeared, and they afforded a better food supply
for the subsequently increased land-animal life. The
insects underwent a radical change. The
resting stages
evolved to meet the demands of suspended animation
during winter and drought.
59:6.8
Among the land animals the frogs reached their climax in
the preceding age and rapidly declined, but they
survived because they could long live even in the
drying-up pools and ponds of these far-distant and
extremely trying times. During this declining frog age,
in Africa, the first step in the evolution of the frog
into the reptile occurred. And since the land masses
were still connected, this prereptilian creature, an air
breather, spread over all the world. By this time the
atmosphere had been so changed that it served admirably
to support animal respiration. It was soon after the
arrival of these prereptilian frogs that North America
was temporarily isolated, cut off from Europe, Asia, and
South America.
59:6.9
The gradual cooling of the ocean waters contributed much
to the destruction of oceanic life. The marine animals
of those ages took temporary refuge in three favorable
retreats: the present Gulf of Mexico region, the Ganges
Bay of India, and the Sicilian Bay of the Mediterranean
basin. And it was from these three regions that the new
marine species, born to adversity, later went forth to
replenish the seas.
59:6.10
160,000,000
years ago the land was largely covered with vegetation
adapted to support land-animal life, and the atmosphere
had become ideal for animal respiration. Thus ends the
period of marine-life curtailment and those testing
times of biologic adversity which eliminated all forms
of life except such as had survival value, and which
were therefore entitled to function as the ancestors of
the more rapidly developing and highly differentiated
life of the ensuing ages of planetary evolution.
59:6.11
The ending of this period of biologic tribulation, known
to your students as the
Permian, also
marks the end of the long
Paleozoic
era, which covers one quarter of the planetary history,
two hundred and fifty million years.
59:6.12
The vast oceanic nursery of life on Urantia has served
its purpose. During the long ages when the land was
unsuited to support life, before the atmosphere
contained sufficient oxygen to sustain the higher land
animals, the sea mothered and nurtured the early life of
the realm. Now the biologic importance of the sea
progressively diminishes as the second stage of
evolution begins to unfold on the land.
Presented by a Life Carrier of Nebadon, one of the
original corps assigned to Urantia.
*
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