Full image caption
Pre-historic fossilized tooth or toadstone found in Upper Jurassic sediments. A polished hemispherical crushing tooth of Lepidotus Maximus, a fossil fish. In the 16th and 17th century this natural dentition was known as a 'toadstone' presumably because of its warty, mottled brown/grey and domed appearance, and they were worn to protect newborn infants and as an antidote against poison. Lepidotus maximus is found in Oxfordshire within Upper Jurassic sediments approximately 150 million years old. Part of the Cheapside Hoard.
© Museum of London