Devonian Acanthodian (Primitive Shark) Fossil (Pos/Neg) - Scotland

This is an enrolled specimen of the Early Devonian, Acanthodian primitive shark, Diplocanthus striatus. It was collected from the Sandwick Fish Beds in the Old Red Sandstone in the Orkney Isles of Scotland. Both the positive and negative sides of this split are included.

Acanthodii is a class of teleostome fish that share characteristics of both cartilaginous fish and bony fish. Discoveries of acanthodians suggest that they first appeared in the Silurian Period and lasted roughly until the early Permian Period.

Diplacanthiformes (clade of Acanthodii) are considered the earliest jawed vertebrates and are best known for their fin spines and abundant scales. Fortunately articulated specimens are relatively common, allowing for scientific study and some insight into their lifestyles.