What is a fossil? Quite simply stated, a fossil is the remains or evidence of any creature or plant that once lived on the Earth. Most often it is the remains of a dead animal or plant or the imprint left from the remains of such. Though I certainly don’t know enough about this subject to know what classification this fossil would fall into, It appears that one of the more common finds, as in this case, is the hardened shell of some type of ancient invertebrate. If you take a careful look of a close-up on the right, you will notice two things. At the left edge you get to see the curvature of the outer portion of the shell, giving you a 3-D effect of what the shell was actually like. Looking at the center of the specimen you can actually make out the inside “ribs’ of the shell.