| Description | University of Michigan, Ann Arbor; Museum of Paleontology; Charles N Miller, Jr.; Egbert G Driscoll.
See: Fenton, C L; Hibbard, C W, Curator of Vertebrates; Arnold, Chester, Department of Botany, Curator of Fossil Plants; Shull, A F; Stumm, E C, Curator of Paleozoic Invertebrates; Ehlers, G M, Curator of Paleozoic Invertebrates; Copeland, M J, Department of Mines and Technical Surveys |