Exceptional fossil tooth of Otodus megalodon, the largest shark ever known to have inhabited Earth's oceans and one of the most iconic marine predators in Earth's history. This authentic specimen measures 5.5 cm in length and displays the classic triangular and robust morphology characteristic of Megalodon teeth. The natural grey-brown coloration is the result of mineralisation processes that occurred over millions of years, giving the fossil its distinctive appearance and unique character. The tooth retains well-defined serrated edges and part of the original root matrix, enhancing both its scientific and aesthetic appeal. A restoration is present at the tip of the tooth, carried out to stabilise and preserve the specimen for display purposes. Otodus megalodon, whose species name means "big tooth" in Greek, lived from the Early Miocene to the Early Pliocene, approximately 23 to 3.6 million years ago. Fossil discoveries from around the world indicate that this giant shark had a cosmopolitan distribution. Although it was once considered closely related to the modern great white shark (Carcharodon carcharias), more recent studies classify it within the extinct family Otodontidae, a lineage distinct from that of living lamnid sharks. Estimated body lengths for Megalodon range from approximately 14 to over 20 metres, making it one of the largest predatory sharks ever to exist. This fossil tooth represents a remarkable piece of natural history and is an excellent acquisition for fossil collectors, palaeontology enthusiasts, educational collections, or as an impressive display specimen.