title: Wormlike fossil from the pennsylvanian of illinois.
abstract: Tullimonstrum gregarium was a common, possibly marine, invertebrate in certain shallow, offshore waters of northern Illinois during the Middle Pennsylvanian. It had a flexible proboscis armed with teeth; a mobile tail; and a curious transverse bar behind the head, bearing a pair of round, external organs.
authors.forename: E S
authors.initials: ES
authors.lastname: Richardson