The mid-Ordovician observed the 1st cephalopods with septa solid plenty of to cope With all the pressures related to further drinking water, and could inhabit depths bigger than Squid one hundred200 m.[139] The path of shell coiling would prove to generally be important to the long run success with the lineages; endogastric coiling would only permit large dimensions for being attained with a straight shell, While exogastric coiling at first alternatively