James Ellsworth De Kay, an American physician and naturalist, was born Oct. 12, 1792. De Kay came to the U.S. as a child from Portugal, studied at Yale and Edinburgh, and took up residence in New York City, where he affiliated himself with the recently founded Lyceum of Natural History. In 1825, De Kay read two papers to the Lyceum, both of which were vital in the founding of invertebrate paleontology in the United States. The first described a trilobite that had been dug out of the limestone at Trenton Falls gorge, about 15 miles north of Utica in upstate New York. He announced that it differed from the four genera of trilobites that had been discovered so far in Europe, and he named it Isotelus gigas. De Kay accompanied his short paper (third image) with two plates, one of which we see above (fourth image). Isotelus gigas was the first of thousands of Ordovician trilobites that would come out of Trenton Falls gorge. We have a lovely book in our History of Science Collection, American Scenery; or Land, Lake, and River: Illustrations of Transatlantic Nature (1840), a collection of views of the American landscape by William Henry Bartlett, and one of his scenes shows the High Falls in the Trenton gorge (second image).
In his other paper of 1825, De Kay announced the discovery of a fossil invertebrate that was contemporary with trilobites, but much bigger. This fossil was found, not at Trenton Falls, but at a nearby location in Oneida County. It had been discovered in 1818, by Samuel Mitchill, the founder of the Lyceum, but Mitchell thought the flat, paddle-propelled body was that of a catfish. De Kay realized that it was an arthropod, not a fish. He called it Eurypterus remipes, which means “oar-footed broad-wing.” We now know that eurypterids were voracious predators of the Ordovician and Silurian eras, and the largest of them were the largest arthropods who ever lived on earth. De Kay announced the discovery of the very first one in his second paper of 1825 (fifth image) published, like the first, in the initial volume of the Annals of the Lyceum, accompanying it with the first illustration ever of a eurypterid (first image).
De Kay later joined up with the Geological Survey of New York to publish the Natural History of New York State, and he compiled the first section, the Zoology of New York, which appeared in 5 volumes between 1842 and 1844. We have the complete 25-volume set in our History of Science Collection. The Zoology volumes have many fine illustrations of mammals, birds, and reptiles, most of them by John William Hill, but none of them depicted specimens that were as novel or as influential as the trilobite and the eurypterid of 1825.
Harvard has an entire website devoted to Trenton Falls gorge and its importance in the history of American invertebrate paleontology. The site includes a number of contemporary views of Trenton Falls; we especially like the Currier and Ives print, where the people have been greatly reduced in size, making the falls seem enormous (sixth image).
Dr. William B. Ashworth, Jr., Consultant for the History of Science, Linda Hall Library and Associate Professor, Department of History, University of Missouri-Kansas City. Comments or corrections are welcome; please direct to firstname.lastname@example.org.