In 2009, John Scannella and Denver Fowler supported the separation of T. prorsus and T. horridus, noting that the two species are also separated stratigraphically within the Hell Creek Formation, indicating that they did not live together at the same time.
in 2009 john scannella and denver fowler supported the separation of t prorsus and t horridus noting that the two species are also separated stratigraphically within the hell creek formation indicating that they did not live together at the same time