This 50 million year old, Eocene-Era fossil fish comes from one of the world's famous Laggerstatten, the Green River Formation in Wyoming. A small portion of the fish fossils from Green River exhibit such fine preservation. The significant extent of soft-tissue preservation that makes the site famous is evident in this specimen.
This is an exquisite, museum quality juvenile Stingray specimen known as Heliobatis radians (Order: Rajiformes; Family: Dasyatidae), at once a rare and highly sought species, and the only species of ray from this formation. The preservation is superb and the preparation is the best there is. Heliobatis is highly sought not only for the rarity, but also because a specimen such as this makes for an awesome display.
Rays belong to the Chondrichtyes, as do the sharks. All have an inner skeleton made of cartilage. Since cartilage comprises more organic material (collagen and elastic tissues) than bone, it decays more rapidly. As a result, fossils of cartilaginous fishes generally are rare.
The artistry of the preparation would make this an ideal display specimen, and a welcome addition to any collection of fish from the region.