Trace fossils are not actual fossils, rather what is left from the creature or fossil being there. Think of dinosaur foot prints or tracks from wild animals, or the rub marks on trees from bucks rubbing the velvet off their horns.
Worm Burrows
Cephalopod Imprint
Bivalve (Clam) Trace
Where they connected themselves to the rock boring into it.
Maclurites Cast