Most of the fossils that Cuvier mentioned in his paper on living and fossil elephants had already been described and discussed by others; but one of them, as he noted, was a recent discovery. Cuvier made this the subject of a separate paper, which he read at the Institut National not long after his first. It greatly increased his personal stake in the field of fossil anatomy.

Fossil bones are usually found scattered and disarticulated. However, one almost complete assemblage of bones, clearly derived from a single individual of some large animal, had been found in 1789 near Buenos Aires in what was then Spanish South America. Shipped back to Madrid, these bones were assembled at the Gabinete Real (Royal Museum) by Juan-Bautista Bru (1740-99), a conservator there. the most important separate bones and Bru's mounted reconstruction of the whole skeleton were drawn and engraved for him in preparation for a paper he planned to write about it. in 1796 a French official who was visiting Madrid saw the skeleton and obtained a set of Bru's unpublished plates. These were sent to the Institut in Paris, and Cuvier was asked to report on them. in . . .