The Washington times. [volume] (Washington [D.C.]) 1902-1939, 1919-06-08
Science Is Now Able to Trace the
Through Various Changes for e
Explain Just What Developed
the Huge Tusks and Caused the
Nose to Keep on Growing
BY Dr.. w. II. BoIlou.

After many thousands of years Lake
Moeris, or the swAmpy overflow of the
Nile, grew dryer. The Moeritherium
climbed to dry land and grew into the
Palaeomastodon, or Every early mastodon,"
sn animal about the size OF a small pony
with relatively much larger nose and tusks
than the Moeritherium.
Stretching out his nose for roots and
reaching it upward out Of the water for
air started it on the way to becoming a
trunk.
The Palaeomastodons multiplied enor-
mously in ancient Egypt in the Lower
Oligocene period about 100000 years ago.
after centuries of change at their
birthplace in Northern Africa" writes Pro-
fessor Barbour, "their migrations took
them throughout Africa, northward into
Europe and the British Isles, into Euro
ASIA India and Siberia, into North Amer
lea, thence into South America While
the tusks and trunks were developing
until they became ponderous during the
ages required for these mutations and
migrations, the superficial area of the skull
was also increasing. Otherwise there
would not have been the extent of surface
necessary for the attachment of muscles
and ligaments to carry the ever-increasing
load.
"At first the proboscis, or trunk, was
small, but little more than a prehensiIe
lip, much like that of the horse, and used
in much the same way to guide food into
the mouth. In later types perfection Of
specialization was attained by this re-
markable organ. This also added weight
to the skull"
Note the interesting fact that weight of
tusks and trunk led to increase Of brain
space, and hence to growth of intelligence
in the elephants.
When the neck became short, the trunk
had to grow longer.
The next distinct form that evolved
after Palaeomastodon was the Tetrabelo-
dan, whose name means flour teeth" The
evidence of the bones indicates that the
animal was at one time returning to
swampy life, for the increasing lower
tusks and jaws are adapted to digging in
the mud.
THE lower jaw gradually heightened,
reaching its extreme length in TetrabeIo-
don longirostris of the lowe Pliocene
period" says Professor Barbour. Later
the lower jaw decreased in length as the
lower tusks disappeared. while the upper
tusks heightened into the extreme of the
last Of the mastodons, Americans.
The ancestral probOscidean had a num-
Der OF teeth, after the manner of typical
mammals, and these were erupted in the
usual way; that Is, by new teeth pushing
upward and gradually displacing the old.
AS teeth became too large, they were re-
duced in matured adults to one large.
specialized tooth in each jaw.
"Tusks are incisor teeth, which grow
from persistent pulps."
Tetrabelodon lived all over the world
from Egypt, Europe and Asia to America.
and especially Nebraska. This was the
first proboscidean that began to look like
a genuine elephant. He had a long trunk
and tusks. The latter were at first turned
down for digging in the mud, and this
lower Jaw was in some species six and one.
halt feet in length. intermediate forms
between Palaeomastodon and Tetrabelodon
must have travelled from the Old World
10 America by way Of the Arctic land
bridges, and there given rise to the second
type. 0o0Onu
variety OF this elephant-like creature
called Tetrabelodon WiIIistoni becauso
the remains were found bv Professor
Wllllston, lived in Nebraska. II had
shorter lower jaw and longer
trunk than the earlier TYNE
After Tetrabelodon came En-.
belodon. the earliest tvna
OF m""'odon, still in the