Only during their last days in the field, after dreadful walks through knee - deep mud, they made a truly exciting discovery in 66 million year - old rocks: The fossil remains of a particularly large skull of a Mosasaur, a giant sea lizard. (thescienceexplorer.com)
The bones of a dinosaur parent or caretaker — whose large skull is at left — lie curled around the skeletons of many dino babies. (discovermagazine.com)
In particular, having larger skulls relative to their body size allowed birds to evolve relatively large and more elaborate brains. (newscientist.com)