Crayfish are freshwater crustaceans. Their fossils are rare around the world. The few collectible examples available usually originate from China or Mongolia

You get this RARE Extinct Fossil Crayfish - Real Fossil - Freshwater Crustacean. Preserved in layered limestone. It looks like there is a patch of glue/restoration on the darker areas of crayfish (see photo). US seller

• Scientific Name: Palaeocambarus licenti
• Location: Liaoning province, northeast China
• Geological Formation: Yixian Formation
• Age: Early Cretaceous/Upper Jurassic - 120-128 million years
• Size: body of fossil crayfish measures almost 2" (excluding claws) on matrix about 5.5" x 3" x 0.75", weight about 6.9 oz