This is a light colored 1.66" great white tooth shark tooth fossil is from the lower jaw. It has a good serrations and a really nice root.
The ancestor of the modern day great white shark, the Carcharodon Carcharias or prehistoric great white shark is believed to have reached up to 30 feet long and would have been a fierce predator in the ancient oceans, possibly competing for food with the megalodon shark.
The ancient great white would have lived during the era of the megalodon shark around the Miocene to Pliocene era which means this fossil is between 3 and 16 million years old. It is thought that the ancient great white would have competed with smaller and mid size megalodons for food as well as eaten some of the same whales and ancient manatees.
The video below shows shark teeth being found in a dark water river. The tooth above is not in this video but this gives you an idea of how I find these teeth.