Question: how do you know how old the fossils are and where are they found

Duncan Murdock answered on 22 Mar 2010:

We know how old fossils are by dating the rocks that they are found in. We can do this in two ways – the first is to look at the sequence of rocks stacked on top of each other (the ones at the bottom must be older than the ones higher up). Then sometimes you find minerals that contain radioactive elements, by looking to how much they have decayed we can work out how old the minerals (so alsio the rocks they are in) are. By combining these two techniques (known as relative and absolute dating) we can put a date in most rocks.

The fossils I look at mostly come from Shropshire, but also Siberia and South Australia. But you can find lots of different kinds of fossils in lots of places.