St. Landry democrat., 1893-09-23
THE AGE CT MAMMALS,
HOW THE EARTH LOOKED BE
FORE THE AGE OF MAN.

tertiary AGe-Iho Mammoth An
mails Which Once Roamed Owe
North America.
With the tertiary age, or the age o
mammals, modern history of geological
times began. During this age tie Mort
American continent gradually attainc
Its present geographical outlines. ~
the continent, especially its western por
ton, continued to rise above the level O
the ocean, the great sea of the crctaceou
period, which extended from the Mex
lean Gulf toward the Arctic Ocean, /,
first became vast inland sea. Subse
quently, as the elevation Of land contin
ued, this great sea was gradually broker
up into several great lakes, existing be
tween Western Dakota, Nebraska, Kan
sas and Texas and Eastern Oregon an(
Southeastern California. Further up
lifting Of the western portion of the con
tinent gradually caused also these lakes,
with few exceptions, as for instance
The Great Salt Lake, to disappear The
Columbia, Colorado, Missouri and sew
eral other western branches of the Mis-
sissippi gradually carried the waters o.
these lakes to the oceans, and "the great
American desert" on both sides of tho
Rocky Mountains remained to tell the
tale.
Thus the staked plains of Texas and
New Mexico, the bad Lands of South.
western Dakota, the deserts of Eastern
| Oregon, Nevada, Arizona and South
eastern California, and some other
"alkali flats of our Western States are
the legacy left by the great cretaceous
| sea.
The famous canyons of the Colorado
and some other Western rivers, the re-
markable mesas, or table lands of the
American deserts, the numerous terraces
of plateau and the often remarkable fan
tastic formations resembling towers,
castles, Notifications and the like met
with in some localities of these regions,
are also to some extent due to the great
cretaceous sea. This, with its succeed
ing lakes, had, in course of time, de-
posted immensely deep layers of COM
paratively soft sands and cays, through
which water, from rivers and rains,
gradually made its way In various direc-
tons, cutting deep channels, occasionally
from 5000 to more than 6, 0CO feet deep,
washing away vast areas of strata and
leaving only some curiously shaped ter
raced plateau, pillows, cones or hills
standing.
The gradual uplifting of the entire
western half of North America continued
to 60 on during the tertiary age, which
succeeded the cretaceous period. Dur
ing this age the coast chain was elevated,
and through assures of the Sierra and
Cascade ranges vast lava floods were
poured ont over great portions of North
ern California, Oregon, Washington and
to a considerable distance into British
America, covering an area of $40 miles
long and 100 wide, with lava which in
some locations is from 2,OO) to 5000
deep. These lava floods are considered
to have been the most extensive known.
The great elevation of the western
portion of the continent since the creta-
ceous period, and the consequent grad
ual disappearance of the great crctaceous
sea naturally brought about some i'm
portant changes of climate Still this
remained considerably warmer than it is
at present. About the beginning of the
tertiary age the climate of the present
Northern Dakota, rs is inferred from
the palms, figs and other plants
then growing there, was similar to
that of Southern Louisiana or Flori-
da at present. And about the
middle of this age magnolias and other
plants now fiourishing only in Southern
swamps and forests still prospered in
Greenland. And towards the close of
this age elephants, rhinoceroses and other
animals which at present live only in far
more southern countries still swarmed !
about the Upper Missouri Yet with the |
tertiary age began the modern geological |
history OF our globe. During the same |
the geographical outlines of our contin- I
ent were substantially completed, and |
The plants and animals gradually put on
4 modern appearance. Now for the first
lime perfectly Towering plants tlourished.
Now oaks, naples, palms and other trees
If modern type became abundant. Now
bees and other flower loving
Insects began to swarm, and true or per
ect mammals, both herbivores and car
livores (plant and flesh cating), as rhi-
loceroses, camels, elephants, deer, dogs,
'ats, horses and monkeys, besides birds
" modern type, as owls, eagles, wood
,eckers, ETC., made meadows and forests
ing with life.
The wide geographical distribution of
10Th plants and animals of the same
,eneral kinds during this age indicate
hat Asia, Africa, Europe aud America
we're then connected with one another
" land. Africa was connected with
europe by an isthmus over the present
traits of Gibraltar, and by another
sthmus with Italy, as the numerous
ossil remains of elephants, hippopot-
mi and other animals now living only
u Africa, found in the caves of Malta,
icily and Spain, indicate Asia was
onnected with Africa by the isthmus of
uez; America was connected with Asia
y an isthmus over the present Behring
trait, and perhaps with Europe over !
Ireenlaud, Iceland, the Farce and the
british Islands. {
Long before the tertiary age began ]
australia had become permanently separ- {
ted by water from the other continents, '
> the absence of all higher mammalian t
'rms indicate. The mammals Of Aus |
ALA all belong to the lowest mammalian t
7pes, the marsupisls and monotremata, !
18th the exception of few kinds of s
ice, which may perhaps have originally {
ome over from Asia on floating trees or E
God. The more highly developed man. {
'als of Europe, Asia, Africa and Amer
a have almost entirely exterminated the
'wer marsupials wherever they came in {
intact with them, and would undoubt- c
lily have done the same in Australia,
I'd not water barred their way to this
land continent.
The tertiary age, during which plants '
Id animal life fourished ahnndantlv