Fossil air mattresses

To find out what the first animals actually looked like, we have to travel a little further in time, down to your wrist - that's about 550 million years ago. We've found a lot of very strange-looking fossils from this period. They are called 'Ediacaran' fossils, and were named after the nearest settlement to where they were first found in the Flinders Ranges in South Australia. They are the remains of very strange creatures, rather like air mattresses and tyres, though a bit smaller. Some resemble jellyfish and are as big as a dinner plate. Others are similar to long strands of puffy

First animals appear

The man who first discovered them was a geologist called Reg Sprigg. When Reg was exploring in the Flinders Ranges in the 1940s, people thought the rocks were so old there wouldn't be any fossils in them. Nobody seems to have told Reg, because he found hundreds, and more than a dozen different types.

A little while after, in the early 1960s, a schoolboy called Roger Mason discovered a fossil far away in England that looked just like one that Reg had found. A mad keen collector, Roger also went looking for fossils where there weren't meant to be any, in a place called Charnwood Forest. What he found was an amazing fossil - like a big leaf. This was another of these strange, animal-like Ediacaran fossils.

Leaf Fossils

As with all animals and plants, whether living or fossil, it was scientifically described and given a name, Charnia masoni. All living things have two names. The first is the genus name; the second the species name. Your dog is Canis familiaris (and where was it when that pesky cat was in your garden?). A wolf is very similar to a dog and is in the same genus, but it has a different species name, and so it is called Canis lupus. It's a bit like your name, but the other way round. Your 'genus' name is your family name, the same as your mum's and dad's. Your 'species' name is your own - Tim, Katie, Carlos, Farouk, whatever. So when Roger Mason's fossil was formally named, it was given its own genus name (Charnia after Charnwood Forest), while the species was named after its finder, and became masoni.

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Ediacaran fossils have since been found in many other parts of the world, like Canada, Russia and Namibia, and all in rocks of the same age. And all of them are gutless wonders. I'm not meaning to be rude here, it's just that even though the fossils are well preserved, palaeontologists can't find any sign of a mouth, or a gut, or an anus.

So how did these creatures feed? How did they digest their food? How did they go to the toilet? The answer to all three questions is the same: we just don't know. Perhaps they just soaked up food through their skins.

Trust uu^Aorii neoA a+oi^t.

One scientist has suggested that maybe the Ediacaran fossils weren't animals at all, but lichen. These are the green patches you sometimes see on rocks - they grow so slowly they make sloths look like Olympic sprinters.

Another scientist has suggested that the Ediacaran fossils were neither animals nor lichen. He thinks they may have been a form of life quite different from anything living today.

Whatever they were, they seem to have lived a peaceful, quiet life, gently floating around in warm, shallow seas. But this idyllic life was soon to be shattered. Some creatures appeared that changed the whole course of life on this planet for the next 500 million years. These were animals that were fed up with eating sushi (seaweed). They had taken a fancy to sashimi (raw seafood). The first meat-eating predators had arrived.

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