Large Ammonite Fossil From Morocco 7.5 X6.5,9 Pounds

Large Ammonite Fossil From Morocco 7.5 X6.5,9 Pounds . Giant ammonite fossil from Morocco The group Cephalopoda is divided into three subgroups: coleoids (including squids, octopuses and cuttlefishes), nautiloids (the nautiluses) and ammonites. Ammonites' shells make the animals look most like nautiluses, but they are actually thought to be more closely related to coleoids. 'Some of their morphology was closer to that of the coleoid group,' says Zoë. 'We think it’s more likely that ammonites would have had eight arms rather than lots of tentacles like a nautilus, though the shell is more similar to that of a nautilus.' Ammonites were born with tiny shells and, as they grew, they built new chambers onto it. They would move their entire body into a new chamber and seal off their old and now too-small living quarters with walls known as septa.