The genus Edmondia was first described by de Koninck in 1841. The book is Description des animaux fossiles qui se trouvent dans le terrain carbonifére de Belgique, written in the French language. The genus occurs from 252.3 to 457.5 million years ago. It died out during the Permian–Triassic extinction event.
One of the best specimens of the genus Metacoceras that I currently have. Metacoceras is one of the two most common species of cephalopod found in the Brush Creek Limestone. I have difficulty assigning a species. Even in the Treatsie on Invertebrate Paleontology, there is a belief that there are