TWO PREHISTORIC CEMETERIES--GIANT REPTILES AND GIANT TREES
Although reptiles appeared first in the period known as the
Carboniferous Age, or age of plant life, they did not attain their
greatest development until Jurassic and Cretaceous times, when many were
of prodigious size and ruled the world. The gigantic ichthyosaurs,
mesosaurs, and dinosaurs held dominion over the sea and land, and the
monster flying reptile, the pterodactyl, over the air.
Ages ago a great inland sea embracing Wyoming and the surrounding region
occupied the area east of the Rocky Mountains. For many years students
of geology had found this section a fertile field for the study of rock
formations and the collection of fossils; but not until 1898 was the
geological wonderland of central-south Wyoming discovered.
This discovery proved to be a graveyard of prehistoric monsters dating
back probably several millions of years ago. Entombed in the rocks of
the Jurassic and Cretaceous periods, many lizard-like animals of
gigantic size called saurians were found. Several fossil skeletons of
these animals have been chiselled out of the solid rocks and mounted in
museums, the work entailing a vast amount of labor and expense. The
discovery was made by Mr. Walter Granger, who had been sent out by the
American Museum of Natural History, of New York, to hunt for fossils.
In the desert section near Medicine Bow River, Wyoming, he found what
seemed to be a number of dark-brown bowlders. On a critical examination
they proved to be ponderous fossils that had been washed out of a great
bed of reptilian remains. The fossil graveyard in question was found to
be two hundred and seventy-five feet in thickness. Near by was a Mexican
sheep-herder's cabin, the foundations of which were constructed of huge
fossils. The vicinity was christened Bone Cabin Quarry. Ten miles south
of the Bone Cabin Quarry, in the Como Bluffs, another bed containing the
remains of huge dinosaurs was discovered. From these remarkable
cemeteries many fossils have been obtained.
The term saurian means "lizard," and it has many prefixes to indicate
the different genera and species. The prefixes generally express to a
certain extent the characteristic appearance or habits of the different
kinds of saurians. Some were flesh-eaters; others were herbivorous. Some
lived on land; others, in the shallow waters and lagoons, fed on
succulent aquatic plants; still others frequented the deeper waters and
lived on fish.
[Illustration: _Property of the American Museum of Natural History_
The Brontosaurus (herbivorous dinosaur)]
The name dinosaur, meaning terrible lizard, represents an order of
fossil reptiles. They are allied to the crocodile, but, like the
kangaroo, their hind legs were much longer than their front ones. The
neck and tail were very long and the body short but of immense size.
These monsters were from twenty to eighty feet in length and weighed
from thirty to one hundred tons. The long, slender neck supported a
small head that contained a correspondingly small brain, from which it
is thought that the creature possessed a low order of intelligence. The
tail was much thicker than the neck and in some species was flattened.
When rising on its hind legs and resting on its tail it could look into
the window of a four-story building. Some of these strange animals had
bills like those of a duck; some possessed teeth for grinding and others
sharp teeth for tearing. These were by far the largest land animals that
ever lived. The different species often waged titanic battles with one
another for the supremacy of the earth.
It is conjectured that their disappearance was due to violent upheavals
of the earth, to the draining of the water, to changes of climate, and
to deprivation of suitable food.
The mounted brontosaur in the American Museum of Natural History, New
York, will enable one better to appreciate the size of these giants of
the ancient world. This typical specimen, though not the largest found,
is sixty-seven feet long and stands fifteen and one-half feet high. Its
neck measures thirty feet in length and its tail eighteen. The body
weighed about ninety tons. This huge fossil, enclosed in its stone
matrix, was sent from the quarry to the museum. After it had been
received two men were employed constantly for nearly two and one-half
years in removing the matrix, repairing, and mounting the fossil.
Let us turn now to the burying ground of a giant forest. Long, long
years ago, before man appeared on the earth, an inland sea occupied what
is now the northeastern part of Arizona. It was a sea bordered with
sandstone and surrounded by coniferous forests, where stately trees
nodded in the breezes.
At length there came a great change. The rim of the basin gave way, and
the great volume of water, freed from restraint, overwhelmed the forest
with earthy material, prostrating and burying it deep beneath the flood
of sand.
In time the woody structure disappeared, and was replaced by beautifully
stained opal and agate. Again, in the lapse of time the old forest bed
was once more lifted above its former level, forming a mesa, or plateau,
of considerable extent. During subsequent ages, the elements scarred and
furrowed the plateau, forming canyons, gulches, valleys, and buttes,
thus revealing in part this ancient forest. Could these dead trees but
talk, how interesting would be their story! We can read their history
but imperfectly by examining the mutilated breast of Mother Earth, in
and on which lie these mute stone trees, dead yet made more beautiful
through their transformation.
[Illustration: _Property of the American Museum of Natural History_
The Allosaurus (carnivorous dinosaur)]
This region is called the "Petrified Forest," or "Chalcedony Park." It
is about one hundred square miles in extent, and is visited annually by
thousands of people from all parts of the world. On account of its
strange geological character it is of special interest to the scientist.
Let us make a brief trip to this wonderful stone forest. We take light
hand-baggage and board a Santa Fe train. The railway passes near the
most interesting part of the forest, and we change cars before entering
Arizona in order to take this line. The railway officials have made a
station at Adamana, six miles from the edge of the forest, in order to
accommodate the travelling public. We leave the train here and procure a
team to carry us to the forest.
Unless informed of what is to be seen one is apt to be greatly
disappointed. One's idea of a forest is usually that of a timber-covered
area in which the trees stand erect, with outspreading branches; but we
look in vain for a standing tree, or even a stump that is erect.
All are branchless trunks, prostrate on the ground, many wholly or
partly buried; moreover, they are lying in all sorts of positions, some
entire and others broken into sections; some are massed closely
together; others lie apart; and millions of pieces of all sizes are
scattered around. At places we can travel a long distance by stepping
from one log to another.
But what is that pile of variegated disk-like objects looking like the
primitive Mexican ox-cart wheels? They are cross-sections of stone logs,
some large and some small, seemingly thrown together carelessly. It is a
characteristic of petrified trunks to break into cross-sections or
blocks, varying from a few inches to several feet in length; and this
tendency prevails here.
We are told that the trees of this forest antedate those of the
Yellowstone Park by a long period of time. How the loftiest flights of
the imagination are piqued as we contemplate the marvellous changes
since this primeval forest depended on the soil and sun for their
life-giving elements! As we wander through this wonderful forest our
feet seem to be treading on the rarest gems. And well may it seem so,
because when polished these pieces display a beauty of coloring and a
lustre that rivals the glint of precious stones. There is no other
petrified forest in the world in which the mineralized wood assumes so
many varied and interesting forms and colors.
Many years ago a firm at Sioux Falls undertook to manufacture table
tops, mantels, pedestals, and various decorative articles out of
sections of this agatized wood by cutting them into the desired forms
and polishing them. Tiffany and Company, the famous jewellers, also used
this material for the base of the beautiful silver testimonial presented
to the French sculptor, Bartholdi.
At a later date, an abrasive company of Denver conceived the plan of
grinding up these trunks to make emery because of their extreme
hardness; in fact, a plant was shipped to Adamana station for that
purpose. Fortunately for the public, however, it was not put into
operation because the company learned that a Canadian firm had put on
the market an article at such a reduced price that to grind up these
beautiful logs would be unprofitable.
Fragments, branches, and trunks of all sorts and sizes are found lying
around, many of them richly colored, forming chalcedony, opal, and
agate; some approach the condition of jasper and onyx.
Before the Petrified Forest was set aside as a national park by
Congress, many acts of vandalism were committed, to say nothing about
the quantities of mineral carried away by manufacturing firms and
curiosity-hunters. Keepers now have charge of the park, and no one is
permitted to take away specimens for commercial use. Previously many of
the finest logs were destroyed by blasting in order to procure the
beautiful crystals which are found in the centre of many of them.
One object of special interest in the park is the National Bridge, a
petrified trunk which spans a chasm thirty feet wide and twenty feet
deep. The part of the trunk crossing the gulch lies diagonally and is
forty-four feet long. The length of the trunk exposed by erosion is one
hundred and eleven feet; a fraction still remains embedded in the
sandstone.
The ruins of several ancient Indian pueblos are scattered about the
park, nearly all of them built of logs of this richly colored, agatized
wood. The forest was a storehouse for ages, whence primitive men
obtained material from which to make agate hammers, arrow-heads, and
knives, as is shown by implements found hundreds of miles distant from
these quarries.