1. Algeo TJ, Berner RA, Maynard JB, Scheckler SE (1995) Late Devonian oceanic anoxic events and biotic crises: “Rooted” in the evolution of vascular land plants? GSA Today 45(5): 64–66
2. Archibald CL, Pillmore EA (1996) Footprints i. t. rocks: New evidence that dinosaurs flourished on land until terminal Cretaceous impact event. Lunar and Planetary Institute Contributions: 825–890
3. Arkell, WJ, Furnish, WM, Kummel, B, Miller, AK, Moore, RC, Schindewolf, OH, Sylverster-Bradley, PC & Wright, CW (ed) 1957. Cephalopoda, Ammonoidea. The Geological Society of America, Inc. & The University of Kansas, Boulder, 490 pp.
4. Avise JC, Ball R M (1990) Principles of a genealogical concordance in species concepts and biological taxonomy. Oxford Surveys in Evolutionary Biology 7: 45–67
5. Ax P (1984) Das Phylogenetische System. Systematisierung der lebenden Natur aufgrund ihrer Phylogenie. Fischer, Stuttgart, New York