One Of Earth's First Animals Is A Lot Like A Roomba Vacuum

Scientists are discovering new things about Earth all the time, and one of the latest discoveries may be the first multicellular animals to have ever lived. The Ediacara Hills in South Australia's Nilpena Ediacara National Park are home to fossils of organisms preserved as they began to evolve into the first complex, macroscopic animals. It was there that fossils of Quaestio simpsonorum, estimated to have lived 555 million years ago, were discovered by Scott Evans, Florida State University Department of Earth, Ocean and Atmospheric Science's assistant professor of geology, and a team of paleontologists from multiple institutions.

Described in the findings published in Evolution & Development, Quaestio simpsonorum had a thin membrane exterior that connected resilient tissues with left-right asymmetry. Evans said in a statement to Florida State University News, "The animal is a little smaller than the size of your palm and has a question-mark shape in the middle of its body that distinguishes between the left and right side." He also noted that no other fossils from the Ediacaran geological period have had such definitive organization.

Additionally, the animal likely had a motile lifestyle, moving along the ocean floor like a Roomba vacuum while absorbing nutrients, such as microscopic algae and bacteria, through its skin. Harvard University organismic and evolutionary biology graduate student and coauthor Ian Hughes commented, "One of the most exciting moments when excavating the bed where we found many Quaestio was when we flipped over a rock, brushed it off, and spotted what was obviously a trace fossil behind a Quaestio specimen — a clear sign that the organism was motile; it could move."

The paleontologists excavating Nilpena Ediacara National Park's nearly 150,000 acres have been doing so for decades. However, Quaestio simpsonorum was found at a new dig site in collaboration with South Australia Museum volunteers and is extremely insightful at helping researchers understand the evolution of Earth animals, even from single-celled organisms, the smallest living creatures in the ocean, long before the Cambrian period.

Evans noted, "Determining the gene expressions needed to build these forms provides a new method for evaluating the mechanisms responsible for the beginnings of complex life on this planet." The park's lead scientist and Evans' former doctoral adviser, Mary Droser, has been guiding digs in the park for more than 20 years. She explained that Earth is the only planet known to have life so far, and through confirming or disproving the different theories of evolution, this discovery could shed light on potential life on other planets.

The team is keen to reexamine some of the sites they have already excavated because they keep finding new things. Hughes said that even though Quaestio simpsonorum were part of one of the world's first animal ecosystems, they were very diverse, adding that the researchers have seen an eruption of life in that fossil record.