Ordovician Graptolite
Phyllograptus sp.
Ordovician
Garden City Formation
Boss Canyon
Utah
 
Graptolites are colonial animals widely recognized as hemichordates. These fossils are from the Middle Cambrian through the Lower Carboniferous (Mississippian).The name graptolite comes from the Greek graptos meaning "written", and lithos meaning "rock", as many graptolite fossils resemble hieroglyphs written on the rock.