Just six years after Jefferson sent his Megalonyx bones to the American Philosophical Society, Meriwether Lewis came to Philadelphia. Lewis's tutor in the science that thirty years later would be named paleontology was Caspar Wistar (1761-1818) who almost certainly used the Megalonyx bones and mastodon teeth as lecture props.1 The experience must have inspired Lewis to start thinking about the importance of fossils as evidence of species possibly still to be seen alive in the plains, mountains and forests beyond the Mississippi River.
Caspar Wistar was a Philadelphia Quaker physician and educator who was an heir to the glass manufactory wealth amassed by his grandfather, Caspar (1696-1752). Young Caspar was educated in Edinburgh, where he received his medical degree in 1786. He would not officially become a professor of anatomy until 1808, but at the time Lewis arrived in 1803 he was already an accomplished comparative anatomist, studying and teaching about the differences between comparable organs and bones and their functions in different kinds of animals.
Perhaps Wistar himself thought that fossils were among the least likely targets of the travelers as they trekked to the Pacific Ocean. This stood to reason. Unlike the useful geological productions of the territory that Lewis was to observe and report upon, such as lead, coal and salt, fossils had no practical worth beyond that of anatomical study and scholarship. Nevertheless, the exploring or hunting parties just could be fortunate enough to track roaming mastodons, for example, known hitherto only by their mammoth-sized tusks and bones.
But what would be the prize in the American West? Mastodons or megalonyxes? Mastodons were of great interest to scientists and the general public alike. To the lay person they carried strange names, like "the incognitum"–"unknown"–or geographically specific names, such as in the case of one famous specimen called "the Ohio animal." The excavation of one mastodon in particular was attended to in 1799 by Charles Willson Peale and his son, Rembrandt, at the farm of John Masten in the Hudson River valley of New York. The elder Peale publicized it and a few years later magnificently illustrated the scene in a painting. This was one of two mastodon skeletons collected by Peale along the Hudson River (the other in 1801), both of which were mounted and displayed in his Philadelphia museum.
Mastodons (and mammoths) were such enigmatic animals because they resembled elephants but were so much larger. Mastodons and mammoths sometimes are conceptually confused; they are quite different animals, which added to the confusion about them. Although their skeletons differ from each other as much as each differs from the modern elephant, the easiest distinction between them is in their teeth. Mastodons have teeth with blunted points, with which they easily crushed sticks and twigs in their diet–and for this reason some early paleontologists believed the mastodon to be a carnivore, and because of its great size, perhaps even a predatory one. The teeth of mammoths are flatter, with undulating, parallel ridges well suited for grinding the grasses that comprised its diet.
Still, the problem remained about where the remains of these elephant-like creatures were being found. Who in the world had heard of elephants living in such inclement climes as Ohio and New York–not to mention the mammoths whose bones (and whole frozen bodies!) were found in the Siberian tundra? And, being also very big, they were very popular with a paying museum public. Surely Meriwether Lewis visited Peale's museum in 1803 and there saw the eleven-foot-tall incognitum in its reconstructed glory. A few years later, a number of fossils would be among the boxes of "natural productions" that were shipped from the West to Jefferson and awaiting scientists. What the boxes lacked, though, were mastodon teeth and bones.
1. This is information that was never recorded. There is much about Lewis's program of instruction when he was in Philadelphia that was never written down or reported to another diarist or correspondent. Another example of this glaring omission is seen in Lewis's botanical training, that we do not know how his mentor instructed him, nor how Lewis actually did press the plant specimens while in the field. He was trained in botanical identification and preservation by Benjamin Smith Barton, who, lacking an American guide to native plants, had assembled in 1795 a set of pressed plants in two bound volumes that he called "Flora Americana." It is inconceivable that Barton did not use the volumes in 1803 while instructing Lewis in botanical systematics and taxonomy, as well as in how to press plants; but there is no known written record of this. And so there is the same lack of evidence in Lewis's paleontological training with Caspar Wistar. The two volumes of "Flora Americana" are presently on long-term loan from the American Philosophical Society to the Academy of Natural Sciences, as part of the Benjamin Smith Barton herbarium. [For more on the botanical collections and later conjecture on how they were prepared, see several sources: 1) Moulton, Journals, Vol. 12, Herbarium of the Lewis and Clark Expedition (Lincoln: University of Nebraska Press, 1999); 2) Earle E. Spamer and Richard M. McCourt, "The Lewis and Clark Herbarium of the Academy of Natural Sciences, Part 1, History," Notulae Naturae no. 475 (2002); 3) Richard M. McCourt and Earle E. Spamer, Jefferson's Botanists: Lewis and Clark Discover the Plants of the West (Philadelphia: Academy of Natural Sciences 2004); and 4) Richard M. McCourt and Earle E. Spamer, "On the Paper Trail in the Lewis and Clark Herbarium," Bartonia, no. 62 (2004), pp. 1-24.]
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