Original description
K. A. v. Zittel. 1890. Handbuch der Palaeontologie. I. Abteilung Paleozoologie. III. Band. Vertebrata (Pisces, Amphibia, Reptilia, Aves) [Handbook of Paleontology. Division I. Paleozoology. Volume III. Vertebrata (Pisces, Amphibia, Reptilia, Aves)]