The cliff and beach are rich in reptile remains, including complete skeletons. Lilstock also yields ammonites, shells and fish remains. A unique specimen of an ichthyosaur, named  Excalibosaurus costini  McGowan, 1986 in which the lower jaw is shorter than the upper was found in the Lower Jurassic Sinemurian Stage, Lower Lias beds on the foreshore at Lilstock and is now in the Bristol City Museum and Art Gallery.
The cliff and beach are rich with reptile fossils, including complete skeletons.  Lilstock also yields ammonites, shells, and fish remains. A unique ichthyosaur specimen, *Excalibosaurus costini*, was discovered at Lilstock in the Lower Jurassic Sinemurian Stage, Lower Lias beds on the foreshore.