Cladiscites – a surviving cephalopod

After the devastation of the extinction event at the end of the Permian only a few species of cephalopods survived – a pattern this group encountered in several other mass extinctions. Cladiscites was an ammonoid cephalopod. Although the fossil has a series of ornate squiggle patterns, these were internal structures called sutures that were not on the shell’s outer surface. Other fossils of Cladiscites show that the shell’s surface was finely ridged.