Answer:
ancient sharks
Step-by-step explanation:
Nicholas Steno can be considered as the father of paleontology. In the year of 1666, Steno received a shark specimen caught by two fishermen. Once he started dissecting it, he noticed that the teeth have very interesting shape. They reminded him of the ''tongue stones'' known since the antiquity. In fact, the ''tongue stones'' were actually teeth of ancient sharks, just that the people were not aware of that. Steno was quick to see the similarities, thus he made a conclusion that they have to be connected.