Image: Crystalline tubes seen in rocks (left) might have been formed when the collagen-like skeleton of an 890-million-year-old sponge decayed and fossilized. Some modern sponges have internal scaffolding (right) that resembles the shapes in the rocks. Credit: Elizabeth C. Turner
In a study published in the latest issue of the journal Nature, it was noted that a Canadian geologist may have found the oldest fossil record of animal life in the world. Elizabeth Turner, from Canada’s Laurentian University, has found 890-million-year-old sponge fossils in the rocks that she had been examining since the 1980s in the Northwest Territories state.
The study reminds that about a billion years ago, the region of northwestern Canada, now covered with steep mountains, was a prehistoric marine environment where ancient sponge remains could be preserved in mineral deposits.
Geologist Elizabeth Turner has discovered new rocks in a remote area accessible only by helicopter at the excavation site in the Northwest Territories state, and thin sections of these rocks contain three-dimensional structures resembling modern sponge skeletons.
As a result of the dating of the adjacent rock layers, the specimens were determined to be approximately 890 million years old, indicating that it was 350 million years older than the oldest animal fossil ever found in the world.
Many scientists believe that the first groups of animals included sponge-like creatures with characteristics of simple animals, including soft sponges or cells without muscles and nerves, but with different functions and sperm.
While the scientific world argues that life on Earth began about 3.7 billion years ago, they argue that the first animals appeared much later and when exactly that happened.
Scientists agree that the arguably oldest sponge fossils ever date to some 540 million years ago, called the Cambrian period.
Some scientists say that the available evidence shows that sponges emerged much earlier, about a billion years ago, but have not found any physical evidence to support this until today.