Ammonites are extinct marine mollusks that lived from about 400 to 65 million years ago. Known for their spiral-shaped shells, they belong to the cephalopod family, closely related to modern-day squid and nautilus.

Ammonites thrived in ancient oceans, and after their extinction, their shells were buried in sediment, eventually fossilizing. These fossils - named ammolites - often found in stunning colors and intricate patterns, are highly valued by collectors and studied by scientists to understand Earth's prehistoric marine environments. 

Ammonites come in many varieties, with shells ranging from smooth and coiled to ribbed or spiny, reflecting their diversity through the ages.