Clonograptus

Clonograptus is a genus of graptolites. Groups of these animals were connected by stalklike structures to a central region. Species of Clonograptus are zone fossils, that help us estimate a precise age of Ordovician rocks. ...
Found on http://en.wikipedia.org/wiki/Clonograptus

Clonograptus

genus of graptolites (extinct, small floating colonial animals related to the primitive chordates), characterized by a frondlike form. Groups of ...
Found on http://www.britannica.com/eb/a-z/c/98
No exact match found