Phosphorus could be the mystery ingredient that pushed oxygen levels in the oceans to establish the first animals on Earth, a study has said.

The first animals on Earth were known to have been established 750 million years ago, according to Kurt Konhauser, a University of Alberta geomicrobiologist and his PhD student Stefan Lalonde.

They found phosphorous in the debris of the last glacier that encircled the Earth and later was washed into the oceans, after it receded.Phosphorous is a nutrient for the growth of blue-green algae and its byproduct is oxygen.

The higher oxygen levels in the ocean could have a reached a level that favored the evolution of animals.

"Now in 2010 we showed that phosphorus levels actually peaked between 750 and 635 million years ago at the very same time that oxygen levels increased, allowing complex life forms to emerge," says Lalonde. "That establishes our link between phosphorus and the evolution of animals."