This is a classic US trilobite. It is a very large Isotelus maximus from Ohio. This type of trilobite is recognized as the State Fossil of Ohio. This specimen is tightly enrolled - the tail is perfectly tucked under the head, which is extremely unusual. The genal spines are intact and have been prepared free-standing, making for a great display. And the bug sits on its natural matrix - not composited. This is a massive enrolled example of this classic US trilobite.