Animals older than ancient

Studies of fossils in China are extending knowledge of ancient animals back by about 30 million to 40 million years before the Cambrian explosion, the 'evolutionary divide' previously thought to signal the sudden appearance of complex life.

Two teams of palaeontologists have found the minute but distinct traces of ancient marine animals and embryos exquisitely preserved in phosphate deposits. The specimens are related to sponges, jellyfish and even more advanced species, including apparent forerunners of trilobites, clams and crabs.

Under a magnifying glass, tiny mineralised organisms reveal striking details down to the cellular level, clearly establishing the abundance and diversity of ancestors of today's animals at least 570 million to 580 million years ago.

Moreover, the discovery of such early fossil organisms, which are more complex than sponges or jellyfish, leads scientists to suspect the initial appearance of multicellular animal life must have occurred much earlier than previously believed. Genetic studies have recently hinted the first simple forms of animal life may have emerged half a billion years before the Cambrian explosion.

Facing up to man on Mars So is there, or isn't there, a face on Mars? On July 25, 1976, the Viking mission seeking potential Mars landing sites took pictures of the ground which, when processed, looked to NASA scientists like a face. Others said the 'face' had been purposely shaped and showed there was, or had been, human-type life on Mars.

Last week NASA fulfilled its promise to take a second set of pictures of the controversial land form with the Mars Global Surveyor spacecraft, currently orbiting the Red Planet, to address the question.

Here are the results: on the left is the Viking photo, and on the right is the processed image taken last week, with 10 times better resolution than the Viking picture.