Excavations have revealed deposits of both burnt and unburnt human bone in the passage, indicating human corpses had been placed within it, some of whom had been cremated. From examining the unburnt bone, it was shown to come from at least two separate individuals, but much of their skeletons were missing, and what was left had been scattered about the passage. Various grave goods were deposited alongside the bodies inside the passage. Excavations that took place in the late 1960s and early 1970s revealed seven 'marbles', four pendants, two beads, a used flint flake, a bone chisel, and fragments of bone pins and points. Many more artifacts had been found in the passage in previous centuries by visiting antiquarians and tourists, although most of these were removed and went missing or held in private collections. Nonetheless, sometimes these were recorded and it is believed that the grave goods that came from Newgrange were typical of Neolithic Irish passage grave assemblages. The remains of animals also have been found in the structure, primarily those of mountain hares, rabbits, and dogs, but also of bats, sheep, goats, cattle, song thrushes, and more rarely, molluscs and frogs. Most of these animals would have entered and died in the chamber many centuries or even millennia after it was constructed: for instance, rabbits were only introduced to Ireland in the thirteenth century.