The earliest known animals on Earth - sponges that lived 890 million years ago on the mainland, are now found in northwest Canada. This conclusion was reached by scientists from the University of Lawrence in Sudbury.
The strange sponges were discovered on the fossilised Little Dal reefs in Canada by Palaeontologist Elizabeth Turner, who described them as «sponge like-structures». If her findings are confirmed and these fossils do turn out to be the remains of ancient sponges, they will precede the current oldest known sponge by about 350 million years.
Moreover, they will be evidence that animal life emerged 90 million years earlier than previously and link it to changes in the level of oxygen in the atmosphere. It was assumed that the animals did not appear until the oxygen level was increased as a result of the so-called Neoproterozoic oxygenation even.
Sponges, the simplest known animal species, are prime candidates for being the oldest biological fossil on Earth. Analysis of the genomes of sponges showed that they first appeared in the early Neoproterozoic from about 1000 to 541 million years ago.
However, evidence of the existence of real fossilized sponges from this period is clearly lacking in the annals of rocks, and Dr. Turner's find was a major event in paleontology.
The full results of the study have been published in the journal Nature.
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