Canada: 890-million-yr-old sponge fossils believed to be the earliest sign of animal life

A Canadian geologist may have found the first sign of animal life on Earth that existed 890 million years ago. The scientist has claimed that sponge fossils discovered by her could date back around 890 million years, that is, 350 million years earlier than the last undisputed animal fossil which is considered to be the oldest.

The findings can be very significant to detect when exactly animal life emerged on Earth as till now there is no conformity to it due to lack of sufficient fossilized evidence. The claim was made by Canada's Elizabeth Turner, a sedimentary geologist and professor with the Harquail School of Earth Sciences at the Laurentian University in Sudbury, Ontario. Her peer-reviewed paper was published by the journal Nature.

Evidence of earliest sign of animal life 

Turner discovered the rocks in a remote region of the Northwest Territories of Canada, where she has been excavating since the 1980s. Thin sections of rock contain three-dimensional structures that resemble modern sponge skeletons.

“I believe these are ancient sponges — only this type of organism has this type of network of organic filaments,” said Joachim Reitner, a geobiologist and expert in sponges at the Germany’s University of Gottingen, who was not involved in the research to news agency AP.

The carbon dating of other adjacent rock layers indicates the samples are about 890 million years old, which would make them about 350 million years older than the oldest undisputed sponge fossils previously found.
 

“What’s most stunning is the timing, to have discovered sponge fossils from close to 900 million years ago will greatly improve our understanding of early animal evolution,” said Paco Cardenas, an expert on sponges at Sweden’s Uppsala University, who was not involved in the research told AP. 

 As per prior researches, many scientists have believed that the first animal groups included soft sponges or sponge-like creatures that lack muscles and nerves but have other features of simple animals, like basic cells and cell organelles. 

Scientists do not cast consensus on Turner's research 

However, Turner’s research has gained no scientific consensus or certainty, so other researchers want to analyze her findings and continue to debate. They have argued that there’s very little scientific consensus or certainty about anything dating back a billion years ago.“I think she’s got a pretty strong case. I think this is very worthy of publishing — it puts the evidence out there for other people to consider,” told David Bottjer to AP. David is a paleobiologist at the University of Southern California, who was not involved in the research.

As is established, it is believed that life on Earth emerged around 3.7 billion years ago and the earliest animals appeared much later, but the exact date is still debatable. Until now, the oldest undisputed fossil sponges dates back to around 540 million years. It was discovered in an era called the Cambrian period.

(With AP Inputs)
(Image: Twitter/@science)