Answer
Charmouth Mudstone, renowned for its rich fossil deposits, especially ammonites and belemnites, fascinated Mary Anning in her fossil-hunting pursuits at Lyme Regis. This sedimentary rock formation dates back to the Late Jurassic period and is highly prized by paleontologists for its paleontological significance. With layers teeming with marine life remnants, Charmouth Mudstone became a treasure trove for Anning's remarkable discoveries.