References
- Bengtson , S. , ed. 1994 . Early life on Earth , x + 630 New York : Columbia University Press .
- Retallack , G. J. 1994 . Were the Ediacaran fossils lichens? . Paleobiology , 20 : 523 – 44 .
- Seilacher , A. 1989 . Organismic construction in the Proterozoic biosphere . Lethaia , 22 : 229 – 39 .