Douglass was elated. This was more than a “one strike”! How much more,
only further digging would tell. Sensing a large-scale operation, he
informed the Carnegie Museum of his prospects and readied things with
the intensity of a man at the gate of destiny. From the neighboring
ranches he recruited men, horses, and equipment. He sent for his wife
and child. He constructed a road to the discovery site, built a
five-room cabin out of logs and lumber, converted a sheepherder’s camp
wagon into an office, selected ground for future planting, bought a cow.
A forge was set up. Tools were purchased.
Back at the museum, Andrew Carnegie, himself, evinced interest. He had
always wanted something “as big as a barn” for his institution. A
special annual field fund of $5,000 was added to the regular budget to
carry on the work.
Within a year, Douglass and his men had run a cut over a hundred feet
long in the hard sandstone, digging down along the almost perpendicular
slant of the rock. At the base of this, rails were laid and small mine
carts introduced to haul away the cuttings from the rapidly developing
quarry.
New specimens appeared: A small plant-eating dinosaur known as
_Dryosaurus_; an armored form called _Stegosaurus_; and another large
creature like the _Apatosaurus_. Best of all, the _Apatosaurus_ No. 1
was well on its way out of the rock and would soon be ready to ship to
the Carnegie Museum in Pittsburgh.
[Illustration: “... I SAW EIGHT OF THE TAIL BONES OF A
_Brontosaurus_ IN EXACT POSITION.” (FROM DOUGLASS’ DIARY, 1909.
SHOWN IN PHOTO IS DOUGLASS’ ASSISTANT, ELDER GOODRICH.)]
[Illustration: THE FIRST CUT IN THE QUARRY, AS IT LOOKED IN 1910.
(COURTESY, A. S. COGGESHALL.)]
[Illustration: SAMPLE VIEW OF DINOSAUR REMAINS AS THEY WERE
UNCOVERED IN THE QUARRY. THIGH BONE NEAR MAN. (COURTESY, A. S.
COGGESHALL.)]
[Illustration: QUARRY OPERATIONS. SAURISCHIAN PLASTERED PELVIS UPPER
CENTER. (COURTESY, A. S. COGGESHALL.)]
In 1913, after 3 years of laboratory work in the Carnegie Museum the big
_Apatosaurus_ was on its feet in the Hall of Vertebrate Paleontology—1
of the 4 mounted specimens of this genus in the country and the most
perfect of all. Prepared and erected by Arthur S. Coggeshall and his
associates, it measures 71½ feet long and stands 15 feet tall at the
arch of the back.
As the excavating progressed it was not long before the diggings became
what is known to the profession as a “general quarry.” Dinosaurs of “all
kinds and sizes” were showing up. Other quarries of this type had been
developed in previous years in the Morrison formation at Como Bluff,
Wyo., and Canon City, Colo., but they contained nothing like the variety
of forms found here. Moreover, these at the monument were better
preserved and the skeletons more intact.
The remains most frequently encountered in the diggings were those of
sauropods—the huge plant-feeding dinosaurs with long tapering
extremities that lumbered about on four pillar-like legs. _Camarasaurus_
and the larger _Apatosaurus_ were typical members of this group, and
their numerous bones show them as being common animals of their time.
More common were the _Diplodoci_, of the exaggerated neck and even
longer whiplash tail. This genus distinguished itself by producing not
only the largest amount of skeletal material from the quarry, but also
the largest number of skulls—those rarest of fossils. One skull was
found in exact position with the neck bones, which settled all doubts as
to the details of this animal’s head piece. The longest _Diplodocus_ to
come from the monument extended 75½ feet.
Contrast this with the diminutive _Laosaurus_, a 2½-foot biped which
ranks as the smallest dinosaur yet taken from the deposit. This tiny
creature had hollow limb bones and was one of the agile, quick-running
types. Only one was found. When discovered, Douglass thought it a “baby”
dinosaur, but study proved it to be a full-grown specimen. The condition
of the skeleton reflected considerable agitation before and after
burial. It lay on its back, the limbs distended. The tail was gone and
the skull crushed.
In many respects, the most interesting dinosaur found was the sauropod,
_Barosaurus_. It was an extremely long-necked form, some of the
individual cervical vertebrae measuring 3 feet in length. Two specimens
were excavated.
The flesh-eaters, as might be expected from their scarcity in other
localities, made but a small showing. Two specimens of _Antrodemus_ were
unearthed. Thirty feet long, this animal was the ranking predator of its
day, although hardly comparable to the towering _Tyrannosaurus_ that
entered upon the earthly scene at a later age.
_Stegosaurus_ remains—so abundant that Douglass grew tired of them—added
a bizarre note. An armored form, it was equipped with a frill of bony
plates that extended the length of the back and terminated in a pair of
sharp spines. Its chief claim to fame rests in its supposed two sets of
“brains,” one a motor-control center situated in the hip region, and the
other in the usual place.
Everywhere they dug, the excavators found fresh material—a vast jumble
of bones so concentrated and intermingled as to make it difficult to
distinguish one specimen from another. Douglass was amazed. Obviously,
it was not with animals of a single area that he was dealing, but of an
entire region. He was dealing with a dinosaur _fauna_. He was also
perplexed. How did so many different types happen to occur in one small
locality?
Slowly, as Douglass’s acquaintance with the deposit grew, the answer
came. It was, he reasoned, the work of a river. The sandstones were
ancient sediments. In their structure and composition lay the story of
swift swirling currents. The coarse granular texture told of fast water;
the crossbedding, of shifting channels; the grouping of the bones into
clusters, of eddies.
It all added up to an old delta deposit at the mouth of a river, a
region of bars where the carcasses of dinosaurs brought down stream
accumulated. Settling, the great hulks became buried as they sank into
the receptive sand. A number of carcasses multiplied ... and slowly, as
flesh and ligament decayed, the bones became mingled, eventually to
petrify and remain preserved through the ages.