While the exact cause of the Cretaceous–Paleogene extinction is still debated, the prevailing theory is that an asteroid or comet impact near what is now Chicxulub, Mexico released massive amounts of heat, dust, and gases into the atmosphere.
Ammonites were among the many marine creatures that perished during this extinction event.
Although ammonites went extinct, their close relatives, collectively referred to as Coleoidea, survived and diversified to give rise to modern cephalopods, including octopuses, squids, and cuttlefish.
It is important to note that the Cretaceous–Paleogene extinction was a global event and it affected various organisms in different ways. While the extinction of ammonites was significant, many other marine and terrestrial species were also wiped out.