Fossil Forest, Dorset

Parts of forest can also be seen on the Isle of Portland and in quarries near the town of Weymouth to the west.

[2] Near the end of the Jurassic period (c.144 million years ago) the sea levels dropped and a number of islands emerged in the Purbeck area, surrounded by saline lagoons and channels.

[2] The c. 140-million-year-old Gymnosperm trees bear similarities with modern-day Cypress (Cupressus), with foliage having the characteristics of a 'Monkey Puzzle' (Araucaria araucana).

[1] Because of its closeness to Cupressus, the species found here at the fossilized forest has been named Protocupressinoxylon purbeckensis[1] (i.e. 'Early cypress-wood from the Purbecks').

[5] Purbeckensis is fairly easily distinguished from other species of prehistoric tree, due to the timbers' characteristic "cross-field pitting".

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.
Protocupressinoxylon from the Fossil Forest