1) Devonian animal 
Bactroceras is a genus of the family Baltoceratidae, orthoceroid cephalopods that lived during the early Middle Ordovician, from about 472—464 mya, existing for approximately 8 million years. ==Taxonomy== Bactroceras was named by Holm (1898). Its type is Bactroceras avus. It was assigned to the Baltoceratidae by Furnish and Glenister(1964) and r...