Rare fossil creatures from a rather mysterious
period known as the Ediacaran are amongst the most exquisite
examples of the earliest complex life.
The 560-575 million-year-old specimens from
Canada, of marine organisms called rangeomorphs, are preserved
in three dimensions, as covered by a report in Science magazine.
The organisms appear to be somewhat plant-like,
with 'frondlets' - leafy structures that branch from stems. These
were probably free-floating, elevated above the sea floor by a
stalk. The organisms may have had an asexual, or vegetative, method
Guy Narbonne, of Queen's University in Ontario,
Canada, found the new assemblage of fossils in an area called
Spaniard's Bay in eastern Newfoundland. The rocks at nearby Mistaken
Point on the island have also yielded Ediacaran fossils, but these
are squashed flat.
Lighting the fuse
At the time of reporting, Dr Narbonne believed
that rangeomorphs were a single biological group, which could not
fully be classified either as animals or as plants. The Ediacaran
period occurs just before the 'Cambrian explosion', an evolutionary
blossoming in which many important animal groups appeared for the
Professor Jim Ogg, secretary-general of the
International Commission on Stratigraphy (ICS), had previously
speculated that the mysterious Ediacaran organisms were probably
'torn to shreds' by the predatory animals that became more common
in the Cambrian (see the earlier feature, The Tragic Life of
the Ediacarans, via the sidebar, right).
The soft-bodied rangeomorphs were probably buried
in a mud-flow, which was itself then covered over by ash from a