vertebrate from the Pennsylvanian geological period

Tullimonstrum, colloquially known as the Tully Monster, is an extinct bilaterian animal that lived in shallow tropical coastal waters of muddy estuaries during the Pennsylvanian geological period, about 300 million years ago. A single species, T. gregarium, is known. Its classification has been the subject of controversy, and interpretations of the fossil likened it to molluscs, arthropods, conodonts, worms, and vertebrates. It is unknown weather Tullimonstrum was a vertebrate or an invertebrate.

Temporal range: Middle Pennsylvanian
Tullimonstrum gregarium 343.JPG
The Tully Monster
Tullimonstrum gregarium fossil
(part and counterpart)
Scientific classification e
Kingdom: Animalia
Clade: Bilateria
Genus: Tullimonstrum
Richardson, 1966
Type species
Tullimonstrum gregarium
Richardson, 1966