Walking on two legs, along with opposable thumbs and braininess, is supposed to be what makes humans human. But a couple of bipedal beasts are challenging that concept.
Duopus: In 2000 in Indonesia, biologist Christine Huffard of the University of California at Berkeley noticed an Octopus marginatus strolling slowly along a sandy bottom on two arms, gathering the remaining six around its body as a disguise. This marks the first known instance of bipedal locomotion in an animal without a rigid skeleton. This might have been an anomaly, but a similar sight greeted her three years later in Australia, where the smaller Octopus aculeatus tiptoed along in the shape of an algae cluster, raising the possibility that the behavior is normal for the invertebrates. How could two arms be better than eight? “Most octopuses have to give up camouflage to move quickly, making it risky for one to escape from ...
