This is a huge, 4.2" long, inflated Asaphus cornutus quarried in the St. Petersburg region or Russia. It looks like it's ready to crawl right off the rock.
Like nearly all of the trilobites from these quarries there is some shell restoration as the shell tends to fracture when the rock is broken. It is mainly along the repaired crack running diagonally through the trilobite and on the tail.
Comes with an acrylic display stand.
Photo of the Vilpovitsy quarry near St. Petersburg Russia where this trilobite was found.
Trilobites were a very diverse group of extinct marine arthropods. They first appeared in the fossil record in the Early Cambrian (521 million years ago) and went extinct during the Permian mass extinction (250 million years ago). They were one of the most successful of the early animals on our planet with over 25k described species, filling nearly every evolutionary niche. Due in large part to a hard exoskeleton (shell), they left a excellent fossil record.