The ancestors of the manatee were one of the first fossil animals in Florida, dating back about 45 million years. The modern manatee has been in Florida about 3 million years. Their teeth are not common throughout the state, but where they do occur they are often abundant. Many are worn down flat and then naturally fall out and are replaced by new ones. That is why they are called “spit teeth.” This same process happened with the mammoths and mastodons also.