Canada: Will an 890 Million Year Old Sponge Rewrite History?

years, which could make it the oldest known animal life on Earth. 890 million-year-old sponge skeletons found in Canada may be the oldest animal life on Earth Fossilized skeletons found in northwestern Canada may have come from ocean sponges 890 million years ago, research showed Wednesday, making them the oldest known animal life on earth. The results also challenge the well-established idea that animals did not originate from Earth until massive oxygen was pumped into the atmosphere and oceans. Sponges are simple animals with an ancient history. Genetic evidence collected from modern sponges has shown that they probably appeared between 1 billion and 500 million years ago. But so far there has been no evidence of fossilized spongy bodies from this period, known as the early modern period. Elizabeth Turner, a professor at the Harwell School of Geosciences at Canadian Laurentian University, looked for evidence of 890 million year old reef sponges created by a type of bacteria that deposits calcium carbonate. During his research journey that spanned the 1980s, Turner discovered networks of tiny tube-like structures containing crystals of the mineral calcite, suggesting they were contemporaneous with the corals, which closely resemble the fibrous skeleton found in some modern sponges. If the structures Turner identified as sponge specimens were verified, they would be 350 million years older than the oldest known sponge fossils. And despite the implications of her potential discovery, which were published in the journal Nature, Turner said she didn’t get carried away. “The first animals to emerge probably looked like sponges,” she said. This is also not surprising, given that the sponge is the most important animal in the animal tree of life. She said the possible sponge was about an inch wide and “could have been small and inconspicuous, and lived in dark corners and crevices under the top surfaces of coral reefs.” If the structures are confirmed as spongy specimens, it means they would have lived around 90 million years before oxygen levels on Earth reached levels deemed necessary to support animal life.