 Many ammonite shells have been found with round holes once interpreted as a result of limpets attaching themselves to the shells.However, the triangular formation of the holes, their size and shape, and their presence on both sides of the shells, corresponding to the upper and lower jaws, is more likely evidence of the bite of a medium-sized mosasaur preying upon ammonites.Some ammonites appear to have lived in cold seeps and even reproduced there.