Answer:
Answer is in Explanation
Step-by-step explanation:
You see Ammonites lived during the Devonian Period up until the Cretaceous Period.
However, during the Devonian Period Earth was entirely covered with water, as the first ammonites died the first big extinction the Ordovician-Silurian Extinction occurred and during that time up until the end of the Cretaceous Period or better known as the Cretaceous-Tertiary extinction occurred.
Then came the ice age which froze up a ton of Earth water.