Pabulite Kill Leftover Evidence and the Food Chain The focus on the food chain is not just because the predator got preyed upon, but also because of another potential evolutionary facet. All cephalopods, in general, have tough rostra or beaks that are hard, pointed and difficult to digest. Fossils from the same period of marine crocodiles and predatory fish, and their stomachs, point to the fact that they were not discerning eaters, gobbling everything down, even the hard beaks. This has been gauged from the remains of a fossilized shark (another Hybodus hauffianus ), from the early Jurassic, also found in Germany. It had a stomach full of undigested belemnite beaks, which likely caused its premature and untimely death.