Squalodon was a primitive marine mammal which lived during the Oligocene to Miocene epochs (33-14 million years ago). It's not known wether these animals were dolphin or another group belonging to the toothed-whale families. Fossils of these animals have been found in Oligocene and Miocene deposits around the world making their range a rather wide one. Their teeth are strange when compared to other dolphins and whales during the same periods making grouping them difficult. The dental features on the teeth vary by position making them relatively complex when compared to other dolphins/whales of the time. It's thought that these animals were around 3 meters (10 feet long) and had a diet similar to extant dophins; bony fish, crustaceans and squid.
 
 Found under SCUBA in the rivers of South Carolina, collecting these teeth is highly specialized and hazardous. Although I do SCUBA dive for teeth, most of these high quality pieces come from a skilled commercial diver whom I consider a personal friend.