An unusual sample of skin from an unusual shark. Actually, its a type of guitarfish (related to rays) that has characteristics of both sharks and rays, hence the common name, shark ray. This creature has a broad flattened head with gills on the underside -- typical of a ray, but it has a more pronounced lower lobe on the tail.
This interesting piece of skin is located just above its eye. It has very large, bony denticles. I've included a picture the head of a whole preserved specimen to better illustrate where this section of skin is located.