A recent fossil discovery in Canada is reshaping scientists’ understanding of early animal evolution.
Deep in the Canadian Northwest Territories, researchers from the American Museum of Natural History and Dartmouth College have uncovered more than 100 fossils belonging to the Ediacaran biota, a group of soft-bodied organisms that lived over 500 million years ago.
The new finding suggests evolutionary developments such as movement, sexual reproduction, and complex body structures appeared millions of years earlier than previously thought.
The Ediacaran Period, which lasted from about 635 to 538 million years ago, marks an important stage in Earth’s history when multicellular life first became widespread. Before then, life mainly consisted of microscopic organisms.
The newly discovered fossils give scientists a closer look at this complex transition from simple microbial life to large, complex marine animals.
Found in the Mackenzie Mountains (traditional lands of the Sahtú Dene and Métis peoples), scientists researching the area discovered fossils belonging to the White Sea assemblage, a group of Ediacaran organisms previously found only in Europe, Asia, and Australia.
A First-of-Its-Kind Discovery in North America
What makes the discovery even more impressive is the age of the fossils. Some scientists estimate the specimens are about 567 million years old, making them 5–10 million years older than any previously known White Sea fossils. The time overlap with the Avalon assemblage points to communities that existed earlier than researchers suggested.
Among the most important fossils found was Dickinsonia, a flat, oval-shaped organism believed to move across the seafloor while feeding on bacteria and algae. Scientists consider it one of the earliest animals capable of movement. Another fossil, Funisia, provides the oldest known evidence of sexual reproduction. This is a tubular organism that releases sperm and eggs into the water during reproduction.
“For 3 billion years, life on Earth was dominated by microbes,” said the study’s lead author, Scott Evans, in a statement. “Then, all the sudden, we get these strange-looking marine animals big enough to see and capable of behaviors we would find familiar today.”
Evans, who is the assistant curator of invertebrate paleontology at the American Museum of Natural History, also emphasized the site’s importance in advancing understanding of the changes organisms were undergoing during this period in our planet’s deep history.
“If we want to understand this transition, when life first became large, complex and unmistakenly animal, this new site has tremendous potential,” Evans said.
Researchers also uncovered Kimberella, an organism thought to be an early relative of mollusks. It has a muscular foot used for scraping food from the ocean floor and could be the oldest known bilaterian. Another interesting fossil is the Eoandromeda, which may be an ancient comb jelly with eight spiral arms.
“Not only is this new site highly diverse, but also it is from a part of the rock succession where we have previously lacked fossil remains,” said study co-author Justin Strauss, an associate professor of Earth and Planetary Sciences from Dartmouth. “This is really exciting. Given our understanding of the regional geology in northwestern Canada, there is great potential here to revisit our understanding of Ediacaran Earth history.”
The fossils also challenge assumptions about where early animals first evolved. Scientists had previously believed shallow coastal waters were the main environment for early animal life. However, the Canadian fossils suggest otherwise, indicating that these organisms lived in deeper marine settings.
Evans believes the results “suggest a pattern where evolutionary innovation begins in deeper environments and later spreads toward the coast.”
“We think of the deep ocean as a dark, inhospitable place, but it is also relatively stable, with few fluctuations in things like temperature and oxygen essential to most animal life,” Evans said. “This stability may have provided key opportunities to support early animal life.”
Chrissy Newton is a PR professional and the founder of VOCAB Communications. She currently appears on The Discovery Channel and Max and hosts the Rebelliously Curious podcast, which can be found on YouTube and on all audio podcast streaming platforms. Follow her on X: @ChrissyNewton, Instagram: @BeingChrissyNewton, and chrissynewton.com. To contact Chrissy with a story, please email chrissy @ thedebrief.org.