Brown, R.H., Richardson, M., Boulter, D., Ramshaw, J.A.M. and Jeffries, R.P.S. (1972) ‘The
amino acid sequence of cytochrome c from Helix aspera Müeller (Garden Snail)’, Biochemical
Journal, 128:971–4.
Butterfield, N.J. (2000) ‘Bangiomorpha pubescens n. gen., n. sp.: implications for the evolution of
sex, multicellularity, and the Mesoproterozoic-Neoproterozoic radiation of eukaryotes’,
Paleobiology, 26:386–404.
Canfield, D.E. and Teske, A. (1996) ‘Late Proterozoic rise in atmospheric oxygen concentration
inferred from phylogenetic and sulphur-isotope studies’, Nature, 382:127–32.
Carroll, R.L. (1997) Patterns and Processes of Vertebrate Evolution, Cambridge:
Cambridge University Press.
Carver, J.H. and Vardavas, I.M. (1994) ‘Precambrian glaciations and the evolution of the
atmosphere’, Annales Geophysicae, 12:674–82.
Conway Morris, S. (2000) ‘The Cambrian “explosion”: slow-fuse or megatonnage?’, Proceedings of
the National Academy of Sciences, USA, 97:4426–9.
Cooper, A. and Fortey, R.A. (1998) ‘Evolutionary explosions and the phylogenetic fuse’, Trends in
Ecology and Evolution, 13:151–6.
Davidson, E.H., Peterson, K.J. and Cameron, R.A. (1995) ‘Origin of bilaterian body plans:
evolution of developmental regulatory mechanisms’, Science, 270:1319–25.
Doolittle, R.F., Feng, D.-F., Tsang, S., Cho, G. and Little, E. (1996) ‘Determining divergence times
of the major kingdoms of living organisms with a protein clock’, Science, 271:470–7.
Easteal, S. (1999) ‘Molecular evidence for the early divergence of placental mammals’, BioEssays, 21:
1052–8.
Fedonkin, M.A. (1994) ‘Vendian body fossils and trace fossils’, in Bengtson, S. (ed.) Early Life on
Earth, New York: Columbia University Press, pp. 370–88.
Feng, D.-F., Cho, G. and Doolittle, R.F. (1997) ‘Determining divergence times with a protein
clock: update and reevaluation’, Proceedings of the National Academy of Sciences, USA, 94:
13028–33.
Foote, M., Hunter, J.P., Janis, C.M. and Sepkoski, J.J. Jr (1998) ‘Evolutionary and preservational
constraints on origins of biologic groups: divergence times of eutherian mammals’, Science,
283:1310–14.
Fortey, R.A., Briggs, D.E.G. and Wills, M.A. (1996) ‘The Cambrian evolutionary “explosion”:
decoupling cladogenesis from morphological disparity’, Biological Journal of the Linnean Society,
57:13–33.
Gingerich, P.D. (1986) ‘Temporal scaling of molecular evolution in primates and other mammals’,
Molecular Biology and Evolution, 3:205–21.
Gray, J. and Shear, W. (1992) ‘Early life on land’, American Scientist, 80:444–56.
Gu, X. (1998) ‘Early metazoan divergence was about 830 million years ago’, Journal of Molecular
Evolution, 47:369–71.
Heckman, D.S., Geiser, D.M., Eidell, B.R., Stauffer, R.L., Kardos, N.L. and Hedges, S.B. (2001)
‘Molecular evidence for the early colonization of land by fungi and plants’, Science, 293:
1129–33.
Hedges, S.B. (2001) ‘Molecular evidence for the early history of living vertebrates’, in P.E. Ahlberg
(ed.) Major Events in Early Vertebrate Evolution: Palaeontology, Phylogeny, Genetics and Development,
London: Taylor & Francis, pp. 119–34.
Hedges, S.B., Parker, P.H., Sibley, C.G. and Kumar, S. (1996) ‘Continental breakup and the ordinal
diversification of birds and mammals’, Nature, 381:226–9.
Hedges, S.B., Chen, H., Kumar, S., Wang, D.-Y., Thompson, A.S. and Watanabe, H. (2001) ‘A
genomic timescale for the origin of eukaryotes’, BMC Evolutionary Biology, 1:4.
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