My first fossils were tiny little fragments in limestone chippings near my home in Hereford, when I was about five. They turned out to be Silurian brachiopod shells brought in from Shropshire, but by the time I knew that, I'd already become hooked. When I went to university at Cambridge my final year project was to produce a geological map of the area between Llandrindod and Llandegeley, and this produced my first significant discoveries: some of the oldest fossil starfish from Britain, and a plethora of unknown sponges.

I promptly went back to the area, known as the Builth-Llandrindod Inlier, for a PhD at Birmingham, looking at how individual volcanic ash beds affected the ecosystems of the time. After that, it was a research fellowship back in Cambridge, and I'm now working in London while waiting for the right lecturing or research job to turn up.

What is so wonderful about the Builth Inlier? Many, many things. It's a volcanic island, 450 million years old, preserved in the rocks as completely as any in the world. The sediments that piled up along its shores, and in the deep water as the island subsided, are full of fossils. The trilobites are famous, and justifiably so, but it is the rarer things that fascinate me; the rarer things, and their communities as a whole. In these rocks are exquisite sponges (one of the most important fossil sponge faunas in the world), echinoderms (sea-lilies, starfish, and the oldest known sea-cucumbers and sea-urchins from anywhere), crustaceans, snails, worms and colonial bryozoans.

There are truly strange things as well: carpoids, conulariids, and other entirely extinct groups. Some of the fossils are preserved so well that even the soft tissue of the organisms is preserved, down to the tentacles of the anemone-like hydrozoans.

What I and Lucy Muir, my collaborator, are really interested in doing is putting together the entire ecological history of the area in as much detail as possible. This is research that is leading to a deep understanding of these lost ecosystems, and allowing us to bring it back to life in our imaginations.

We now have over 350 species from the area, of which nearly two-thirds are previously unknown, and we are beginning to understand the links between the communities. If you like, you can follow our progress or find out more at www.asoldasthehills.org, and join in discussions on our forum.

The most startling discovery we have made is that even in well-known localities, there are new fossil species to be found at almost every visit. If we find a new locality, we expect a few new species per day; even at well-known places we are constantly making new discoveries. No matter how much has been done, there is always more out there. Palaeontology is one of very few sciences in which an amateur can make important contributions with a minimum of resources; anyone can stumble across something remarkable, although not everyone will pay attention to it. Look with an open mind and very open eyes, and you never know what will turn up.

Article written by Joe Botting