While whale bones have been found in South American archaeological sites, they were usually attributed to opportunistic scavenging of stranded animals. The artifacts came from vast shell mounds known as sambaquis, which are abundant along Brazil’s southern coast. These 5,000-year-old harpoon shafts made from whale bones were long hidden along Brazil’s southern coast. The humpbacks came as a surprise, as they had long been absent from Brazil’s southern coast, says Krista McGrath, a biomolecular archaeologist also at Universitat Autònoma de Barcelona. They are also building a catalog of whale species present before European arrival, hoping to inform conservation efforts.