Professor Jim Ogg, secretary-general of the International
Commission on Stratigraphy (ICS), filled in some of the background:
"There's always been a recognition that the last part of the
Precambrian is a special time before the first shelled animals, when
there are these weird, mesh-like creatures of uncertain affinity,"
The Ediacaran period begins at the end of the last ice age of
the Snowball Earth, or Cryogenian Period, a term given to a series
of glaciations that covered most of our planet between 850-630 or
600 million years ago.
One theory proposes that these climate shocks triggered the
evolution of complex, multi-celled life.
Professor Ogg said many of the new life forms that appeared in
the Ediacaran seem to be simple organisms, probably related to
"They appear to be lying flat on the seafloor and people think
they may have had photosynthetic symbiosis much like corals do
today," he explained.
"These organisms were probably ripped to shreds when the first
predators came along. That probably happened in the Cambrian
A life cut short
"Ediacarans were on a trajectory in which they would have
developed into intelligent life, but it was cut short,"
Professor McMenamin agreed in a
report published in the New Scientist magazine.
"They were developing ways to pick up environmental cues and
process that information in ways that would allow them to adapt
better and leave more progeny.
"Ediacarans represent the first evidence of anything like
intelligence on Earth."
Other researchers have dismissed his ideas, claiming the
Ediacarans were in fact the forebears of primitive animals such as
For decades the accepted view was that Ediacarans were animal
Then in 1982, Adolph Seilacher, from the University of Tubingen
in Germany, announced that Ediacarans were not animals at all but a
now-extinct class of life by themselves.