Cambrian Explosion; is real (Introduction)

by David Turell , Monday, June 17, 2013, 14:49 (4177 days ago) @ David Turell

There are no precursors. Ediacarans may have been land forms. Cambrians are all developed in the ocean.-http://www.astrobio.net/pressrelease/5213/ediacarans-on-land -20 million years with these forms, and then the explosion.-Darwin himself very honestly: "Consequently, if the theory be true, it is indisputable that, before the lowest Silurian or Cambrian stratum was deposited long periods elapsed, as long as, or probably far longer than, the whole interval from the Cambrian age to the present day; and that during these vast periods the world swarmed with living creatures...
 
"To the question why we do not find rich fossiliferous deposits belonging to these assumed earliest periods, I can give no satisfactory answer... the difficulty of assigning any good reason for the absence beneath the Upper Cambrian formations of vast piles of strata rich in fossils is very great. It does not seem probable that the most ancient beds have been quite worn away by denudation, or that their fossils have been wholly obliterated by metamorphic action, for if this had been the case we should have found only small remnants of the formations next succeeding them in age, and these would always have existed in a partially metamorphosed condition. But the descriptions which we possess of the Silurian deposits over immense territories in Russia and in North America, do not support the view, that the older a formation is, the more it has invariably suffered extreme denudation and metamorphism.
 
"The case at present must remain inexplicable; and may be truly urged as a valid argument against the views here entertained." 
—Chapter IX, "On the Imperfection of the Geological Record," On the Origin of Species, fifth edition (1869), pp. 378-381.