The Tully Monster is the state fossil of Illinois. It lived 280-340 million years ago when most of Illinois was an ocean. It's found in Mazon Creek. It was a soft bodied animal. It was discovered by Francis Tully.
The Tully Monster is the state fossil of Illinois. It lived 280-340 million years ago when most of Illinois was an ocean. It's found in Mazon Creek. It was a soft bodied animal. It was discovered by Francis Tully.