Earth's first animals formed complex communities, study shows

By Brooks Hays
Paleontologists exaamined Ediacaran fossils in Namibia. Photo by A.F. Darroch
Paleontologists exaamined Ediacaran fossils in Namibia. Photo by A.F. Darroch

Sept. 17 (UPI) -- Until now, scientists thought Earth's first macroscopic animals, the Ediacaran biota, were ecologically simple. But new research suggests the unusual animals formed complex communities.

The Ediacaran biota is comprised of a diversity of blob-like creatures with frond-like patterns. They're revealed by fossil imprints in ancient rocks dated to between 635 and 542 million years ago.


Simple ecosystems are those with limited diversity. They feature only a few dominant life forms, all competing for the same handful of resources. Complex ecosystems look like modern ecosystems, with a variety of species competing for different combinations of resources.

When researchers designed a model to better understand interactions among Ediacaran biota, they found evidence of more complex communities.

"Our analyses support the complex model, illustrating that -- even though they may look bizarre -- these mysterious fossils may have far more in common with modern animals than we thought," Vanderbilt University paleontologist Simon A.F. Darroch said in a news release.

New analysis of Ediacaran fossils from Namibia showed the primitive animals developed a diversity of nutrient collection methods, which allowed the animals to diversify and seek out different resources.


"This result illustrates that the Ediacaran biota may not have been as bizarre as it is sometimes suggested," researchers wrote in their new paper, published this week in the journal Nature Communications.

Previous research showed the arrival of Metazoans -- vertebrates, mollusks, arthropods, annelids, sponges and jellyfish -- during the Cambrian explosion, altered the environment and disrupted Ediacaran ecologies, triggering the demise of the first animals.

Another recent study determined Ediacaran animals, despite their strange appearance, had more in common with modern animals than previously realized.

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