This is a fossilized Sperm Whale Tooth discovered in Hawthorn USA and is dated to the Miocene era between 2.6 - 15 million years.
The sperm whale (Physeter macrocephalus), or cachalot, is the largest of the toothed whales and the largest toothed predator. It is the only living member of genus Physeter, and one of three surviving species in the sperm whale family, along with the pygmy sperm whale and dwarf sperm whale of the genus Kogia. Mature males average 16 meters (52 ft) in length but some may reach 20.5 meters (67 ft), with the head representing up to one-third of the animal's length. Plunging to 2,250 meters (7,382 ft), it is the second deepest diving mammal, following only the Cuvier's beaked whale.