Mawsonia is an extinct genus of prehistoric coelacanth fish, and the largest of this group, up to several meters long. It lived during the Cretaceous period (Albian and Cenomanian stages, about 99 to 112 million years ago). Fossils have been found in Africa and South America. Mawsonia was first described by British palaeontologist Arthur Smith Woodward in 1907.