Authentic articulated mosasaur tail from the Niobrara Chalk of Western Kansas. This is a piece we collected and prepared ourselves. The tail has been placed in an artificial plaster matrix. The matrix measures 29" x 10 1/2" and is about 1 1/2" thick. There are 31 vertebra present. The vertebra are in the original position with exception to the last 5 (very tip of tail) which were eroded out of the matrix. The piece was prepped on one side, set in plaster and then cleaned from the other side so some original matrix still remains. There is repair (gluing pieces together and filling cracks) but no restoration. I'm not sure why some of the bone is darker and changing at cracks, but it is natural and not restoration. Email with questions or if would like additional pictures from different angles.