Difference between relative and radiometric dating of fossils
In 1946, Reg Sprigg noticed "jellyfishes" in the Ediacara Hills of Australia's Flinders Ranges It was not until the British discovery of the iconic Charnia in 1957 that the pre-Cambrian was seriously considered as containing life.
This frond-shaped fossil was found in England's Charnwood Forest, and due to the detailed geological mapping of the British Geological Survey there was no doubt these fossils sat in Precambrian rocks. Misra's discovery of fossiliferous ash-beds at the Mistaken Point assemblage in Newfoundland changed all this as the delicate detail preserved by the fine ash allowed the description of features that were previously undiscernible.
Instead, they were interpreted as gas escape structures or inorganic concretions.
but the firm belief that complex life originated in the Cambrian led to them being assigned to the Cambrian Period and no link to Aspidella was made.
Most disc-shaped fossils decomposed before the overlying sediment was cemented, whereupon ash or sand slumped in to fill the void, leaving a cast of the organism's underside.
In March 2004, the International Union of Geological Sciences ended the inconsistency by formally naming the terminal period of the Neoproterozoic after the Australian locality.
Some Ediacaran strata with the texture characteristics of microbial mats contain fossils, and Ediacaran fossils are almost always found in beds that contain these microbial mats.
Although microbial mats were once widespread, the evolution of grazing organisms in the Cambrian vastly reduced their numbers.
Palaeontologist Martin Glaessner finally, in 1959, made the connection between this and the earlier finds All specimens discovered until 1967 were in coarse-grained sandstone that prevented preservation of fine details, making interpretation difficult. Poor communication, combined with the difficulty in correlating globally distinct formations, led to a plethora of different names for the biota.
In 1960 the French name "Ediacarien" – after the Ediacaran Hills in South Australia, which take their name from aborigine Idiyakra, "water is present" – was added to the competing terms "Sinian" and "Vendian" for terminal-Precambrian rocks, and these names were also applied to the life-forms.