One of the reasons Beth loves geology is because you can go from studying the Moon and Mars as a planetary scientist to studying fossils here on Earth, and it’s all under the same scientific umbrella. Now, I’m not going to say I have some grand love for fossils and such unless they are dinosaurs, but I do share Beth’s fascination for understanding the evolution of life.

In new work published in the Journal of Geophysical Research: Biogeosciences, scientists have managed to characterize the discovery of fossilized algae found in China. The formation where these algae were located dates back to the Cambrian period, about 500 million years ago. That’s interesting in and of itself, but the most interesting part is that the algae have external membranes and cell walls.

Let’s back up just a little. Back in the very before times, some of the first critters here on Earth were cyanobacteria. While these are also known as “blue-green algae”, they are not, in fact, algae. They are similar to algae: both use photosynthesis to obtain energy from sunlight. In fact, cyanobacteria are one of the big reasons we have so much oxygen and made it possible for life as we know it to exist.

But cyanobacteria are relatively simple compared to algae, and the rise of algae accelerated the development of life by creating a more efficient food web. Nutrient transfer between species became easier, allowing for more species to arise.

These recently discovered fossils take the cyanobacteria and early algae another step further. Using scanning electron microscopy and X-ray tomography, scientists found that the fossilized organisms were organized into large spatial patterns — an inner cortex and outer medulla. They look to me like little tiny brains.

And this structure suggests that the organisms were asexual, growing from a round ball of cells into the more complicated collection. Each “brain” lobe contains its own organization of cortex and medulla, too. These new specimens are consistent with more contemporary specimens found in China, which gives us a new timeline for their development.

We’re always on a quest for understanding life in the universe, and with this sample planet of exactly one, we will dig through rocks to find as many specimens throughout time as we possibly can.

More Information

Multicellular Algae Discovered in an Early Cambrian Formation (Eos)

“Characterization of the Multicellular Membrane-Bearing Algae From the Kuanchuanpu Biota (Cambrian: Terreneuvian),” Yajuan Zheng et al., 2021 June 7, JGR Biogeosciences