However , the shell-less Coleoidea ( squid , octopus , cuttlefish ) are abundant today .
All cephalopods with external shells except the nautiloids became extinct by the end of the Cretaceous period 65 million years ago .
The shell-less Coleoidea ( squid , octopus , cuttlefish ) are abundant today .
All cephalopods with external shells except the nautiloids became extinct by the end of the Cretaceous period 65 million years ago .