Isurus retroflexus tooth from Somerville, South Carolina. 

Isurus retroflexus lived during the Eocene epoch (56–33.9 million years ago) and was a fast-swimming predator. Its fossils are found in Europe, North America, and Africa, indicating a widespread range.

Growing up to 10–12 feet (3–3.6 meters), it had distinctively curved teeth, ideal for gripping prey like fish.