Evening star. [volume] (Washington, D.C.) 1854-1972, 1929-07-12
PETR|F|ED BONES
SENT TO MUSEUM
Ton and Half in Shipment
From New Mexico by
Dr.. Gilmore.
BY THOMAS r. HENRY.

approximately ION ana Idll vi
petrified dinosaur bones and remains OF
other prehistoric creatures are on their
way to Washington from the desert
country of Northwestern New Mexico.
They were collected during the past
month by an expedition in charge OF
DR.. C. w. Gilmore, associate curator of
vertebrate paleontology at the National
Museum.
In this desolate part of the San Juan
basin, in the heart of the Navajo In
dian country, DR.. Gilmore found places
where the ground was literally covered
with vertebrate and limb bones OF these
long extinct reptiles. The country never
had been explored before by archie
ologists. and it is likely that several Of
the finds represent specimens new to
science.
The area, DR.. Gilmore said. doubt
less was herding ground of dinosaurs
in the days approximately 9O,O0O,O0O
years ago. when it was a marsh. The
bones On the surface, for the most part,
were so badly broken up that they were
worthless They are known as floats"
valued only because their presence usu-
ally leads to buried deposits in much
better shape. Excavations here hardly
justified the expectations from the
great mass of surface deposits, prob
ably washed down from more noun
famous regions in the course OF mil
lions of years.
Dinosaur Tail Dug Up.
Among the bones dug up was one
complete dinosaur tail, about Is feet
long, with all the bones in sequence
There were also several dinoSaur skulls
DR.. Gilmore also shipped back 20 COM
plete turtle specimens. Large turtles:
differing very little from varieties OF
today. evidently were very abundant IN
the upper cretaceous geological period
represented by the deposits, he said.
This was near the close of the age of
the great reptiles. when mammals were
beginning to appear on earth.
Although most fossil bones are petrt-
fed, many of these are Of solid agate
with beautiful coloring. This, said DR..
Gilmore, was brought about by the
gradual bleaching out OF the bones ana
the absorption of water containing the
agate in solution. AS the animal mat
ter was lost the agate deposits were lett
behind. The process was so gradual
that even the cell structure of the
bones was preserved.
This, he explained, affords one way
of telling whether a dinosaur was a
meat or plant eater. The centers OF
the limb bones of the meat eaters were
,
so that they now are solid agate with
out cellular structure. The plant eat
ers. on the other hand, still reveal the
cellular division under the microscope.
In Enormous Numbers.
Such deposits, DR.. Gilmore said. in
dictate that during the Upper Cretaceous
period dinosaurs existed in enormous
numbers. A few petrif1ed specimens
still remaining must represent thou
sands of animals. But about this time
they disappeared quite suddenly. The
fanciful explanation that they were ex-
terminated by the tiny mammals suck
ing their eggs, he says, probably has
little validity. The determination prob
ably was very gradual and brought
about by the change of marsh land into
desert, thus depriving them of their
food supply. For some unknown rea-
sons, the reptiles could not move fast
enough to escape these changes.
The territory explored, DR.. Gilmore
said, is rich in fossil trees, some of these
also solid agate, which are found in
fantastic forms. They underwent APP
proximately the same process as the
dinosaur bones.
When the specimens reach Washing
ton they will be cleaned and efforts
made to piece them together. Then
they will be checked against similar
bones of known species.
DR.. Gilmore also explored strange
cave in Southern New Mexico, in the
bottom of which the complete skeleton
of an ancient giant sloth was found.
This cave was a natural trap for ami
mails, but 1t Is so difficult to enter safely
that the Smithsonian explorers gave
up their work. It consisted of small
opening in the mountain side. barely
large enough to admit man, which
leads to a sheer drop of 100 feet into
the blackness of the heart of the
mountain.
Tunnel Attempt Fails.
The difficulty of letting themselves
down with ropes was so great that
the Smithsonian party tried without
success to dig tunnels to the interior.
Another shipment of bones of extinct
animals is expected soon from DIR. j. W.
Gidley of the department of vertebrate
paleontology, who is hunting for the
remains of upper pleistocene mammals
in Central Idaho, Oregon and Wash
ington. For several years reports have
been coming into the museum of large
deposits of bones of animals which eX-
listed about $4,000 years ago, of special
interest because this is the time when
human beings may have made their
first appearance on the American Con-
tinent. DR.. Gidley will be on the look
out for human artifacts, such as spear
or arrow heads, among the bones of the
extinct eleDhantS camelS bison and