Billion-year-old micro-fossil rewrites history of plant life on Earth
The fossils turn back time for ancient algae.
It took a microscope to help unlock an ancient seaweed secret. Paleontologists with Virginia Tech announced the discovery of one-billion-year-old seaweed fossils, and suggested the tiny remnants may have ancestral ties to modern land plants we know and love.
The green seaweed is a kind of algae called Proterocladus antiquus. The minuscule fossil shown in a Virginia Tech microscope image is about the size of a flea and comes from northern China.
This artist's illustration shows what the ancient green seaweeds might have looked like.
"Previously, the earliest convincing fossil record of green seaweeds were found in rock dated at roughly 800 million years old," Virginia Tech said in a statement on Monday.
At first glance, the fossil looks like a mess of threads. "These seaweeds display multiple branches, upright growths, and specialized cells known as akinetes that are very common in this type of fossil," said Virginia Tech paleobiologist Shuhai Xiao, co-author of a study published in the journal Nature Ecology & Evolution.
The Virginia Tech team believes land plants evolved from green seaweeds over the course of millions of years. "These fossils are related to the ancestors of all the modern land plants we see today," said Xiao.
This hypothesis on the origin of land plants is not universally accepted. "Not everyone agrees with us. Some scientists think that green plants started in rivers and lakes, and then conquered the ocean and land later," said Xiao.
The twisting fossil imprints also resemble some modern green seaweeds. They may be ancient, but they're not unfamiliar.
Originally published Feb. 24, 11:58 a.m. PT.