Graptolithina
![](/Images/godic/202501/16/DiplograptusCaneySprings2641.jpg")
![Graptolite morphology illustrated from the Encyclopædia Britannica.](/Images/godic/202501/16/Graptolites-EncBrit2641.jpg")
![Thallograptus sphaericola, a dendroid graptolite, attached to the cystoid Echinosphaerites aurantium; Ordovician of northeastern Estonia.](/Images/godic/202501/16/Thallograptus2641.jpg")
![Pendeograptus fruticosus from the Bendigonian Australian Stage (Lower Ordovician; 477-474 mya) near Bendigo, Victoria, Australia. Two overlapping, three-stiped rhabdosomes](/Images/godic/202501/16/TetragraptusfruticosusBendigonian2641.jpg")
Graptolithina is a class of hemichordate animal, the members of which are known as graptolites. Graptolites are fossil colonial animals known chiefly from the Upper Cambrian through the Lower Carboniferous (Mississippian). A possible early graptolite, Chaunograptus, is known from the Middle Cambrian.