ammonites are extinct
Ammonites went extinct at the same time as the dinosaurs, about sixty-five million years ago.
in the Mesozoic and Paleozoic era
Ammonites were marine animals that lived in the oceans during the Paleozoic and Mesozoic eras. They inhabited a wide range of ocean environments and are now extinct.
Ammonites are named for the Egyptian god Ammon, who had a ram's head. The shells of ammonites are spirals like the horns of a ram.
Various aquatic reptiles were predators of ammonites. Fossils of damaged ammonites have been found with teeth marks from Plesiosaurs.
Squid
Ammonites first appeared during the Devonian Period within the Paleozoic Era.
Yes, ammonites are good index fossils because they had a wide geographical distribution and existed for a long period of time. Their evolution is well-documented, making them useful for relative dating of rock layers.
Ammonites went extinct at the end of the Cretaceous Period.
Ammonites are very common fossils from the Jurassic Period. They were dominant in the ocean during and before the Jurassic Period.
Ammonites are the most widely-known and abundant fossils in the world. The name "ammonites" came from the Greek god Ammon. Ammonites include squid, octopus, snails, cuttlefish, and nautilus.