REFERENCES
- E.G.Briggs & Peter R. Crowther, Palaeobiology: A Synthesis, Blackwell Scientific Publications, 1990
- Roy R. Lemon, Vanished Worlds: An Introduction to Historical Geology, Wm. C. Brown Publishers, 1993
- Swinton, Fossil Amphibians and Reptiles, British Museum of Natural History, 1973
- Zimmer, C.,Discover Magazine, June 1995