World Octopus Day: new discoveries about the world's smartest invertebrates

Japanese researchers described a fossilized jawbone of Nanaimoteuthis haggarti, an extinct octopus species that may have reached 6.6 to 18.6 meters (22 to 61 feet) in length—potentially among the largest invertebrates ever known. A new species, Microeledone galapagensis, was confirmed from a 2015 deep-sea expedition, and rare photos of developing Patagonian octopus embryos were captured.