SYDNEY: Australian researchers have uncovered the world’s oldest biological colour in the Sahara desert, in a find they said yesterday helped explain why complex lifeforms only recently emerged on earth, reports AFP.

The pink pigments were produced by simple microscopic organisms called cyanobacteria more than 1.1 billion years ago, some 500 million years older than previous colour pigment discoveries.

That makes the samples around “fifteen times older” than the Tyrannosaurus Rex dinosaur species, according to senior Australian National University researcher Jochen Brocks.

Earth itself is about 4.5 billion years old and researchers said the latest find shed light on why more sophisticated plant and animal life only came into existence 600 million years ago.

Previous research argued that low oxygen levels in the atmosphere held back the evolution of complicated lifeforms, but the discovery of cyanobacteria at such an early date suggests that the organisms crowded out more plentiful food sources such as algae.

“Algae, although still microscopic, are a thousand times larger in volume than cyanobacteria, and are a much richer food source,” Brocks told AFP.