Geologists recently discovered marks that closely resemble worm tracks in a piece of sandstone  These marks were made more than half a billion years earlier than the earliest known traces of multicellular animal life
Ttherefore, the marks are probably the traces of geological processes rather than of worms
Most scientists knowledgeable about early animal life believe that worms are likely to have been among the earliest forms of multicellular animal life on Earth, but evidence of their earliest existence is scarce because they are composed solely of soft tissue.