Graptolites

• First Appeared in Early Ordovician.

  Became to dominant marine fauna by late Ordovician/Early Silurian

  Began to decline Middle Silurian

  Extinct Early Devonian
• Nema


  A thin tube, possibly used to attach to a floating object
• Stripe


  A branch of the Rhabdosome
• Theca


  Individual Cup in which one soft bodied organism lived
• Rhabdosome


  The whole structure