But this wasn’t the only scene of mass death to be preserved here in the fossil record. A few kilometers away an earlier drought took a toll of many other animals. The little gazelle-like camel _Stenomylus_ tells the same story in scores of skeletons east of the _Menoceras_ burial ground.
These graceful little camels may have died at the edges of their vanished water hole. The skeletons are mostly undisturbed except for a few pulled apart by meat-eaters. Scores of their dried out, mummified carcasses were buried about the same time as the rhinos on the river’s dry bottom. Like the _Menoceras_, the camels lay there for millions of years, intact in their death poses, the muscles in the backs of their necks pulling their heads back sharply into an unnatural position. There they lay until men discovered them.
Our imaginary journey into the past has reached its end. We have seen a day at Agate as it might have been 20 million years ago. We have watched the animals going about their daily lives during times of plenty and have seen it as it was later, when death’s heavy hand left a magnificent fossil heritage. This unique place is a window into the past, a window through which we can look back at any time and observe life at Agate millions of years ago.
The first fossils were collected in volume in 1904 by Olaf Peterson of the Carnegie Museum in Pittsburgh. Excavations have continued, off and on, to the present. As early as 1892, Erwin Barbour’s student F. C. Kenyon had retrieved a few bones from the site but their significance was overlooked. Rancher James Cook first picked some up in the 1880s and may have first noticed such deposits, without particularly recognizing them, in the 1870s.
Other institutions soon joined Carnegie in extracting slabs of the great _Menoceras_ bone-bed, and occasional _Moropus_ and _Dinohyus_ specimens. The University of Nebraska opened a new quarry in 1905. Henry Fairfield Osborn, president of the American Museum of Natural History and one of the greatest popularizers and exponents of evolutionary science, and his chief preparator Albert Thomson began work in 1907. F. B. Loomis of Amherst College discovered the nearby _Stenomylus_ quarry the same year. Yale University’s R. S. Lull soon followed.