Researchers have discovered the oldest form of complex, multicellular life.
Finding a clump of algae on a rock may not seem like a big deal — but when that rock is over a billion years old, things change.
Indeed, while examining 1.6 billion-year-old fossil records, scientists from the Swedish Museum of Natural History made an astonishing discovery: they found complex, multicellular red algae.
This find has game-changing implications, as current consensus supposes that plant and animal life started to develop roughly 600 million years ago during the Cambrian Explosion.
“Previously scientists have sometimes referred to this period of Earth’s history as the ‘boring billions’ when things are mostly microscopic and not much happens,” Therese Sallstedt, of the Swedish Museum of Natural History, told The Independent. “The fossils we found show that complex life was there already by 1.6bn years ago, but the great radiation of animal life-forms still didn’t happen until 600m years ago.”
Sallstedt was examining fossilized microbes found in Chitrakoot, India, under a microscope when she first noticed the anomaly.
“I got so excited I had to walk three times around the building before I went to my supervisor to tell him what I had seen,” Sallstedt said. “I guess they just waited for the right conditions. That’s like a big mystery…I had seen something similar a little bit before in other thin sections…but the ‘eureka moment’ was when I found this particular specimen when I saw these colonies of algae.”
According to The Independent, little is known about complex, multicellular life from before then, although traces exist.
“What I could see was the fossils were really, really big compared to the bacterial fossils surrounding them,” said Sallstedt. “They were very, very organized in this tissue-like structure in a way you don’t see in the pre-eukaryotic samples. That’s when I realized, wow, this must be more advanced than microbes.”
Sallstedt and her team were able to identify two different sorts of algae, called Rafatazmia chitrakootensis, using x-rays. According to The Independent, one of these algae had a thread-like structure while the other formed the colonies that Sallstedt found.