ARTICLES
A Mop with Tentacles; the Nilpena Fossil Area (continued)
Some scientists believe many of the organisms found at
Ediacara may represent early algae, lichens or even multicellular
‘experiments’, which bear little resemblance to organisms
existing anywhere in the world today. There are many questions
surrounding these ancient organisms; how they lived, how
they evolved and which creatures alive today may be their
descendants. The fossils of this period resemble the flatworms,
soft corals and jellyfish we know today, and range in size from a
few centimetres up to a metre long. This diverse array of fossil
specimens includes anemones, annelid worms, crustaceans,
echinoderms and possible ancestors of trilobites. Other forms
resemble modern sea-pens and worms. Impressions of the
largest early known animals, Dickinsonia rex, have also been
recorded at Ediacara, as well as fossils of what may be the
earliest known ancestor of animals with backbones (vertebrates).
Dickinsonia is interpreted as a worm-like creature, and fossils of
these organisms consist of a flat impression, circular to ribbon-
shaped with fine segmentation.
The Ediacaran Period (Figure 4) was the first new geological
period to be declared in 120 years, and the first to be named
after a location in the Southern Hemisphere. Covering an interval
of around 88 million years from 630 to 542 million years ago, the
start of the Ediacaran Period corresponds to the end of a world-
wide glaciation known as ‘Snowball Earth’ as well as significant
changes in carbon levels. The rapid increase in abundance,
size, complexity and diversity of life forms during this time shows
that the earth underwent a period of major evolutionary change.
Around 30 other Ediacara localities are now known globally,
including sites in Namibia, Russia, Newfoundland, Canada,
UK and Siberia. Some of the greatest examples of this ancient
biodiversity are found in Australia and Russia.
Figure 4. Stratigraphic sequence including the Ediacaran
Period.
Current Research at Nilpena
Dr Mary Droser, from the University of California, comes to
Nilpena each year to explore the Ediacaran fauna in these hills.
She specialises in pre-Cambrian fauna, but prefers to work at
Nilpena. She often stays in the shearer's quarters during the field,
sometimes assisted by her mother, Dorothy.
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SCIENCE EDUCATIONAL NEWS VOL 67 NO 4