1) Transitional fossil
Found on
https://www.crosswordclues.com/clue/archaeothyris
Archaeothyris is an extinct genus of ophiacodontid synapsid that lived during the Late Carboniferous and is known from Nova Scotia. Dated to 306 million years ago, Archaeothyris, along with a more poorly known synapsid called Echinerpeton, are the oldest undisputed synapsids known. (Protoclepsydrops is slightly older, but its status as a synapsid ...
Found on
http://en.wikipedia.org/wiki/Archaeothyris
Archaeothyris is the oldest-known pelycosaur. This long-tailed quadruped lived in warm, humid forests of the early-mid Pennsylvanian period, about 300 million years ago. Archaeothyris looked sperficially like a lizard and was about 20 inches (50 cm) long. This carnivore (meat-eater) had strong jaws and sharp, pointed teeth; it may have eaten small ...
Found on
http://www.enchantedlearning.com/subjects/dinosaurs/glossary/
No exact match found.
