The ammonoids, an extinct subclass of cephalopods, offer a remarkable window into the evolutionary innovations of marine life. Their coiled, chambered shells and intricate suture patterns record a ...

Despite their incredible success, ammonites died out at the end of the Cretaceous in the same mass extinction that killed the ...

Some fossils of long-extinct sea creatures display brilliant rainbow colors. Known as ammolite, these gems come from the fossilized shells of ammonites, squid-like marine animals that vanished with ...

They found that the now-extinct molluscs sported hyponomes: tube-like syphons through which water is expelled to jet propel animals forward in water, as found in modern squid and octopuses. They also ...