The oldest evidence of bioturbation on Earth

Mar 20, 2012

The Ediacaran Period, an interval in Earth's history after the Snowball Earth glaciations but before the Cambrian radiations, marks the introduction of complex macroscopic organisms synchronously in unrelated groups. It has been proposed that the increase in size in marine organisms was triggered by the oxygenation of Ediacaran oceans.

New research shows that animals, rather than a late Neoproterozoic increase in , could equally lead to a revolution in the structure and evolution of marine paleocommunities.

In the course of studying Ediacaran-age rocks in a remote region of arctic Siberia, Vladimir Rogov and fellow researchers from Institute of Petroleum Geology and Geophysics in Novosibirsk (Russia) unexpectedly came across the oldest evidence of bioturbation (disruption of fine-laminated sediments by purposeful burrowing of animals in search for food) that significantly precedes the Cambrian radiations.

Of special interest is that the advent of bioturbation in the fossil record coincides with the earliest ecological differentiation of macroscopic Ediacaran communities, which is interpreted to be a direct consequence of ecosystem engineering by animals.

Bioturbation in modern seafloor habitats substantially affects key ecosystem process, including biogeochemical interactions, , and primary productivity; the first appearance and expansion of bioturbation in the Ediacaran, therefore, must have had a profound effect on ecosystem structure and functioning.

Explore further: Strong quake hits east Indonesia; no tsunami threat

More information: Vladimir Rogov et al., Geology, Posted online 19 Mar. 2012; doi: 10.1130/G32807.1

Journal reference: Geology search and more info website

Provided by Geological Society of America

5 /5 (2 votes)
add to favorites email to friend print save as pdf

Related Stories

Fossils show earliest animal trails

Feb 04, 2010

(PhysOrg.com) -- Trails found in rocks dating back 565 million years are thought to be the earliest evidence of animal locomotion ever found, Oxford University scientists report.

Oldest organism with skeleton discovered in Australia

Mar 08, 2012

A team of paleontologists has discovered the oldest animal with a skeleton. Called Coronacollina acula, the organism is between 560 million and 550 million years old, which places it in the Ediacaran period ...

A new fossil species found in Spain

Mar 25, 2010

In the '80s, Spanish researchers found the first fossils of Cloudina in Spain, a small fossil of tubular appearance and one of the first animals that developed an external skeleton between 550 and 543 millio ...

Fossils on the Edge of Forever

Dec 14, 2009

Astrobiologists have not yet found alien life on other planets. But the fossil record has evidence of aliens of another sort: the Ediacarans that lived on Earth millions of years ago.

Recommended for you

Strong quake hits east Indonesia; no tsunami threat

13 hours ago

A strong earthquake struck off the coast of eastern Indonesia on Sunday evening, but there were no immediate reports of injuries or damage, and authorities said there was no threat of a tsunami.

Scientists make strides in tsunami warning since 2004

Dec 19, 2014

The 2004 tsunami led to greater global cooperation and improved techniques for detecting waves that could reach faraway shores, even though scientists still cannot predict when an earthquake will strike.

Trade winds ventilate the tropical oceans

Dec 19, 2014

Long-term observations indicate that the oxygen minimum zones in the tropical oceans have expanded in recent decades. The reason is still unknown. Now scientists at the GEOMAR Helmholtz Centre for Ocean Research ...

User comments : 1

Adjust slider to filter visible comments by rank

Display comments: newest first

Graeme
not rated yet Mar 21, 2012
One of the features of the Ediacaran has been the lack of bioturbation which destroyed many fossil impressions later in the geologic time. The trace fossil observed is called Nenoxites. It excavates a tunnel up to 5cm deep which is backfilled. The authors call this the first example of engineering, and also the most reliable evidence of the presence of bilaterians. However this was already described in "Planetary Systems and the Origins of Life" see http://books.goog...pg=PA201 which has a picture. It describes the tunnels as being on the underside of the microbial mat, and were known at least since 1990. There have been prior claims of Kimberella being a bilaterian and having feeding traces.

Please sign in to add a comment. Registration is free, and takes less than a minute. Read more

Click here to reset your password.
Sign in to get notified via email when new comments are made.