lodocus_
it was most perfectly developed from its muscular base to its delicate
and whip-like tip, perhaps for all these functions.

_The Three Kinds of Giant Dinosaurs._ It is very remarkable that three
distinct kinds of these great dinosaurs lived at the same time in the
same general region, as proved by the fact that their remains are
freely commingled in the quarry.

What were the differences in food and habits, in structure and in
gait, which prevented that direct and active competition between like
types in the struggle for existence which in the course of nature
always leads to the extermination of one or the other type? In the
last three years we have discovered very considerable differences of
structure which make it appear that these animals, while of the same
or nearly the same linear dimensions, did not enter into direct
competition either for food or for territory.

The dinosaur named _Diplodocus_ by Marsh is the most completely known
of the three. Our very first discovery in the Bone-Cabin Quarry gave
us the hint that _Diplodocus_ was distinguished by relatively long,
slender limbs, and that it may be popularly known as the "long-limbed
dinosaur." The great skeleton found in the Como Bluffs enabled me to
restore for the first time the posterior half of one of these animals
estimated as sixty feet in length, the hips and tail especially being
in a perfect state of preservation. A larger animal, nearer seventy
feet in length, including the anterior half of the body, and still
more complete, was discovered about ten miles north of the quarry, and
is now in the Carnegie Museum in Pittsburg. Combined, these two
animals have furnished a complete knowledge of the great bony frame.
The head is only two feet long, and is, therefore, small out of all
proportion to the great body. The neck measures twenty-one feet four
inches, and is by far the longest and largest neck known in any animal
living or extinct. The back is relatively very short, measuring ten
feet eight inches. The vertebrae of the hip measure two feet and three
inches. The tail measures from thirty-two to forty feet. We thus
obtain, as a moderate estimate of the total length of the animal,
sixty-eight to seventy feet. The restored skeleton, published by Mr.
J.B. Hatcher in July, 1901, and partly embodying our results, gave to
science the first really accurate knowledge of the length of these
animals, which hitherto had been greatly overestimated. The