A representation of the extinct, ray-finned, 319 million-year-old Coccocephalus wildi, a predator estimated to have been 6 to 8 inches long. Castro, Márcio L.

A CT scan of the fish’s fossilized skull was found to have a well-preserved brain inside. Jeremy Marble/University of Michigan News The brain structure of C. wildi’s forebrain more closely resembles that of other vertebrates, rather than that of other ray-finned fish, said the study authors. Figueroa et al. in Nature

A whale belonging to one of the rarest species is ‘likely to die,’ after entanglement, NOAA says