A British geologist and archaeologist who did cave excavation and demonstrated the antiquity of Palaeolithic artifacts by showing that stone tools made by humans were contemporary with remains of extinct animals. At Kent's Cavern, he was able to confirm the conclusions of Reverend J. MacEnery that flint tools were associated with the bones of extinct animals. Though this association was not widely accepted, he continued to find further proof with work at Windmill Cave, Brixham (Devon). He gained academic support and, in 1859, John Evans and several of Britain's leading geologists joined him in contradicting the 4004 BC date as the Creation of man. The discoveries of Jacques Boucher de Perthes in the Somme Valley in France corroborated Pengelly's findings and were used to demonstrate the antiquity of man in 1859, the same year that saw the publication of Darwin's revolutionary "Origin of Species.