stylistic:tone
Extinction

At the time Cuvier presented his 1796 paper on living and fossil elephants, it was still widely believed that no species of animal had ever become extinct. Authorities such as Buffon had claimed that fossils found in Europe of animals such as the woolly rhinoceros and the mammoth were remains of animals still living in the tropics (i.e. rhinoceros and elephants), which had shifted out of Europe and Asia as the earth became cooler.