"The joints of the talons lock, and the weight of the bat's body keeps the talons closed," Pavuk said. In other words, bats spend minimal energy to hang upside down; their bodies are relaxed ...

Mallatt, who was not involved in the new research, published a paper on Pikaia in 2013, working from the established (and upside-down) body position. In retrospect, the truth was “hiding in ...