The mid-Ordovician saw the main cephalopods with septa potent more than enough to manage Along with the pressures connected with deeper h2o, and could inhabit depths higher than a hundred200 m.[139] Squid The route of shell coiling would show to be very important to the long run achievement of your lineages; endogastric coiling would only permit large sizing for being attained with a straight shell, Whilst exogastric coiling at first alternatively