Rise of collagen-eating microbes may help explain gaps in the fossil record

The researchers, led by the University of Cambridge, say that the reason may lie in the evolution of microscopic organisms capable of breaking down collagen, a structural protein found in animal tissue.The fossil record of animal life on Earth is highly incomplete. Hard body parts like shells, bones and teeth are far more likely to be preserved than soft body parts like muscles, organs and skin, so the majority of the fossils we have today are mineralised skeletons.