Evidence of organisms prior to the development of hard body parts such as shells, bones and teeth is especially scarce, but exists in the form of ancient microfossils, as well as impressions of various soft-bodied organisms.
Dokaz organizama koji su živjeli prije razvoja čvrstih dijelova tijela poput ljuštura, kostiju i zubi posebno je oskudan, no postoji u obliku drevnih mikrofosila, kao i otisaka raznih organizama s mekanim tijelom.