Ah yes Squalodon, a genus of shark-toothed dolphins that lived 20 million years ago and is now extinct. This is probably a good thing, a dolphin just wouldn’t be a dolphin if it had shark teeth. That just doesn’t seem right. Although shark teeth may have helped them avoid captivity down the road…

According to the Encyclopedia of Marine Mammals, the Squalodon genus is just one of many fascinating extinct whale groups and types that make up Odontoceti, the sub-order of toothed whales that includes all the dolphins, sperm whale and killer whale.

The oldest fossil fragments of sperm whales date back about 2 million years, pretty impressive. And the oldest dolphin fossil ever found is close to 32 million years old, the Simocetus rayi. This dolphin lived during the early Oligocene age, a much different time when many areas on earth were shifting from tropical forests to woodlands and grasslands. Oh to see what the Simocetus rayi saw, now that would be interesting.