Fossil Forest, Dorset facts for kids

On this ledge are some ring-shaped structures up to 2 metres across. These are moulds of gymnosperms (early coniferous trees) which died after being encased in sediment. Most of the trees were upright leaving round holes, but some had fallen leaving elongate coffin-shaped moulds.

The Fossil Forest is an amazing site in Dorset, England. It shows us the remains of a very old forest from the Jurassic period. This special place is found on a wide ledge in the seaside cliff. It is located east of Lulworth Cove on the Isle of Purbeck. The Fossil Forest is part of the famous Jurassic Coast. You can also see parts of this ancient forest on the Isle of Portland. Some remains are also found in quarries near Weymouth.

How the Forest Formed

Around 144 million years ago, near the end of the Jurassic period, something big happened. Sea levels dropped a lot. This caused several islands to appear in the Purbeck area. These islands were surrounded by salty lagoons and channels. For a short time, soil formed on these islands. A tropical forest started to grow there.

But then, the area flooded again. It became a shallow, salty lagoon. The trees were covered by sediment and water. Over millions of years, these trees turned into fossils. This is how the Fossil Forest was preserved. It is now the most complete fossil record of a Jurassic forest anywhere in the world!

Ancient Trees of the Forest

The trees in the Fossil Forest are about 140 million years old. They are a type of tree called Gymnosperms. These ancient trees look a bit like modern Cypress trees (Cupressus). Their leaves are similar to the 'Monkey Puzzle' tree (Araucaria araucana).

Because they are so much like Cypress trees, the species found here has a special name. It is called Protocupressinoxylon purbeckensis. This means 'Early cypress-wood from the Purbecks'. Scientists have studied the tree rings of these fossils. This study is called Dendrochronology. It shows that these trees grew in a warm, sunny climate. It was similar to a Mediterranean climate today.

Some of the fossil tree stumps have interesting patterns on them. These patterns are from thrombolites. You can also see stromatolites on some stumps. These are structures made by tiny algae.

The Fossil Forest in Dorset is truly special. Experts have called it "one of the most complete fossilized forest of any age."