Carcharocles turgidus teeth. An 8-year-old boy made a prehistoric discovery this month by finding a giant tooth believed to be from the long-extinct angustidens—a megatooth shark species. Riley Gracely of Pennsylvania discovered the massive tooth during a family vacation to Myrtle Beach, South Carolina. According to Palmetto Fossil Excursions (PFE), the boy discovered a 4.75-inch tooth belonging to the extinct shark Carcharocles angustidens while participating in a fossil-hunting excursion near Summerville. "Truly the find of a lifetime," PFE wrote in an Aug. 11 Facebook post. "This young man just scored a 4.75" Angustiden tooth in our Premium Gravel Layer piles...