Between 240 and 65 million years ago, Ammonites could be found throughout the Oceans of the World. They ranged in size, depending on species, with the largest having shells that could grow as large as 1m in diameter. Ammonite fossils are more abundant than those of just about any other creature, since they lived for so many years and in so many places.
Ammonites lived in schools and hunted smaller sea creatures. They consumed their prey through a beak-like mouth hidden among its tentacles.
Ammonites most likely moved around by shooting water from spouts in their bodies. Their actual lifestyle is pretty speculative though, because unlike other prehistoric invertebrates (like Nautelids), the Ammonites have no living relatives.
A final fun fact to start the weekend? The name Ammonite comes from "Amun," an Egyptian god who was frequently depicted wearing spiraled horns (similar to the shell pattern).
Status : Extinct for 65 million years
Location : Oceans worldwide
Size : Varies, up to 1m in shell diameter