The fossil skull sitting on Alexander Kellner’s worktable makes no sense. Usually fossils are spark plugs in the engine of the imagination. One look at the long, gently curved bones of a spider monkey’s arm and you see a graceful swing from branch to branch; one glance at the weighty leg bones of a mastodon and you hear the rumble of a heavy stride. But this skull greets you with cognitive dissonance: all you see is essentially a flat triangle of bone. “A paleontologist once came in here and said, ‘What is that?’ ” says Kellner, himself a paleontologist at the American Museum of Natural History in New York.
Slowly, though, with Kellner’s guidance, the details that will give this triangle meaning emerge. There is a pair of large eye sockets midway along the skull, staring out of a braincase the size of a child’s head; the straight, smooth daggers in front now become a set of jaws. Most prominent on the skull is a crest of bone that starts at the tip of the creature’s beak; it rises above the upper jaw, passes over and behind the eyes, and shoots out behind the skull like an oar. The crest doubles the length of the skull, from two feet to four. How could any creature support such a burden? “It was hollow,” Kellner says simply, picking up a piece of the crest to show how the bone is only a few hundredths of an inch thick in some places. While the crest’s interior is now filled with rock, in life there was only air. It’s all a little less confusing now but no less bizarre.