NOTE: This article is only available to subscribers. Subscribe now to gain access to all articles, read exclusive interviews with top scientists from around the world, and browse the site ad free. The first month is free.

Controversial claim shakes some limbs on the tree of life

December 12, 2012

Controversial claim shakes some limbs on the tree of life

University of Oregon researchers say that ancient multicellular fossils may not be ancestors of early marine life.

A controversial claim has been put forth by a researcher at the University of Oregon that could shake some limbs on the tree of life. Researcher Gregory Retallack argues that ancient multicellular fossils previously thought to be ancestors of early marine life are vestiges of land-dwelling lichen or other microbial colonies.

Mr. Retallack points to Ediacaran fossils as evidence that land creatures may not have come from the sea. Ediacaran fossils date to 542-635 million years ago. They have been thought of as fossil jellyfish, worms and sea pens, but this researcher says that Ediacaran fossils are preserved in ways that are completely different from marine invertebrate fossils. Ediacaran fossils are located in iron-colored impressions like planet fossils and microbes in fossil soils.

Comments should take into account that readers may hold different opinions. With that in mind, please make sure comments are respectful, insightful, and remain focused on the article topic. In addition, readers can send us tips, press releases, or ideas for stories: