Definition of "pelycosaur" []

• A large primitive reptile having a tall spinal sail; of the Permian or late Paleozoic in Europe and North America. (noun)

Gnu Collaboartive International Dictionary of English: licensed under The Code Project Open License (CPOL)

• "Fossil fish in Romer Hall (with a specimen of the pelycosaur Edaphosaurus on the right)."
• "I was under the impression that “therapsid” always referred to a kind of synapsid reptile and was distinct from “pelycosaur” another kind of synapsid think dimetrodon."
• "I had no sooner spoken than I remembered the pelycosaur we had seen in the jungle."