The ancestors of octopuses and squid once sported hard shells, but when did they lose their "mobile homes" and become agile, soft-bodied swimmers? A new study finds that this change may have occurred during the Jurassic and Cretaceous periods.
Imagine you're chopping vegetables when — oops! — you slice your finger. You run to the sink to wash the cut and then ready yourself for the inevitable sting that will come when you put antiseptic on the wound.