tullimonstrum, group of tully monsters swimming in the ocean, the state fossil of illinois 3d

ancient animal arthropod carboniferous carnivore conodont creature eon extinct field form fossil geology green gregarium group history illinois illustration late life light mollusc monster museum nature ocean paleoart paleontology pennsylvanian prehistoric primitive red science shoal species swarm swimming trunk tullimonstrum tully under upper vertebrate water wired worm