The layers of rock in the ancient Andes mountain range became his research site. Fossils of trilobites, brachiopods, fish, crabs and snails, hundreds of millions of years old, all fell within the scope of his collecting.
古老的安地斯山脈岩層成為他的研究場所，上億年的三葉蟲、腕足類、魚、螃蟹、蝸牛等化石都是他的收藏範圍。