13 Nov 2007
Pliosaur, lower Jurassic shale Kettleness
Runswick Bay is formed of lower jurassic (200-175 million years old) shale, and in the 18th and 19th centuries large volumes of the cliff were quarried by the alum industry (excellent article here) to manufacture alum salts, important fixatives in the cloth dying trade. In the course of the quarrying fossils came to light (and fossil bivalves were used by the miners to identify correct type of alum bearing shale). This pliosaur was excavated from Kettleness (below) headland which bounds the southern edge of Runswick Bay. It is now on display in the Natural History Museum, London. Mary Anning, the lady on the display board was an eminent early fossil collector, but had nothing to do with the recovery of this specimen.