Many jellyfish are transparent, and they have seemingly simple movements and few visible interacting parts. They should, therefore, be easy to synthesize with man-made parts, but that's not what bioengineers discovered when they recently built a jellyfish mimic from rat heart cells attached to a silicone frame.

Panda bears are restricted to remote mountains in China and have similar-sized bodies today. But fossils show that in years past some were mini-pandas, while others were giants. Plus, they lived in places far-flung from China. A new find described a mini-panda fossil fragment from Spain, reviving questions about the origin, migration, and demise of panda bears through history.

Octopuses are not warm-blooded animals, yet the speed with which their nerves transmit signals depends on temperature. So how do those that live and move in sub-zero Antarctic waters function just as well as those inhabiting warm, tropical waters? The answer surprised researchers.