This is a very collectible trilobite. It is a large Isotelus maximus from Ohio. This type of trilobite has beed designated the "State Fossil of Ohio". This impressive specimen is tightly enrolled - the tail is perfectly tucked under the head. The enrolled trilobite can be taken out of its natural matrix block, or put back in tightly where one of the long genal spines is still preserved! This is a very displayable "in matrix/free of matrix" example of this classic US trilobite.