The Urantia Book
PAPER 59
THE MARINE-LIFE ERA ON URANTIA
Presented by a Life Carrier of Nebadon, one of the original
corps assigned to 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.
