Orthida is an extinct order of Brachiopods which appeared during the Early Cambrian period and became very diverse by the Ordovician, living in shallow-shelf seas. Orthids are the oldest member of the subphylum Rhynchonelliformea, and is the order from which all other brachiopods of this group stem. Physically they are usually strophic, with well-...
Found on
http://en.wikipedia.org/wiki/Orthida
(from the article `lamp shells`) ...closed by a plate, the pseudodeltidium; dorsal valve with interarea; muscle area narrow and elongated in both valves; 3 genera; Early to ...
Found on
http://www.britannica.com/eb/a-z/o/33
No exact match found.
