Canadian Sponges Nearly a Billion Years Old May Be Earth’s First Animals
Fossils belonging to very ancient sponges dating back nearly a billion years have been discovered in northwest Canada and may be the oldest ever evidence of animal life on our planet.
Geologist Elizabeth Turner made an incredibly significant discovery on rocks located in a very remote area in the Northwest Territories that is only accessibly by helicopter. However, about a billion years ago, this area which is now covered with steep mountains was a marine environment.
In the thin layers of rock, she noticed the fossilized remains of what looked similar to sponges from modern times but they were much older than that. Analysis of the rock layers revealed that the fossils date back approximately 890 million years. This is absolutely jaw-dropping as the previous oldest sponge fossils were 350 million years younger.
A lot of scientists think that the first groups of animals that were present on our planet included soft sponges or sponge-like creatures that didn’t have any nerves or muscles but did have cells with numerous functions as well as sperm. Unfortunately, there isn’t much animal evidence that dates back close to a billion years and that’s why this recent discovery is so fascinating and important.
It is believed that life first appeared on our planet approximately 3.7 billion years ago and that the first animals only showed up many years later but the exact date is still unknown and highly debated.
Since the previous oldest sponge fossil dated back about 540 million years during the Cambrian Period and this new specimen is around 890 million years old, it means that it was around for hundreds of millions of years longer than first estimated and possibly even longer (perhaps a billion years). Since sponges didn’t have any hard shells or skeletons that would have remained preserved over time, evidence of them dating back 890 million years is astonishing.
Paco Cardenas, who is an expert on sponges at Sweden’s Uppsala University but wasn’t involved with the study, stated, “This would be the first time that a sponge fossil has been found from before the Cambrian, and not only before, but way before — that’s what’s most exciting,” adding, “To have discovered sponge fossils from close to 900 million years ago will greatly improve our understanding of early animal evolution.”
Further analysis needs to be conducted on the fossilized sponge, but if it is confirmed to be 890 million years old, it would mean that the first animals to have inhabited our planet would have survived during a time when scientists didn’t think anything would have been able to live based on the small amount of oxygen that was in our oceans and atmosphere. (Pictures of the sponge’s remains found in the Northwest Territories can be seen here.)
The research was published in the journal Nature.
Source: Mysterious Universe