Lulworth skipper their greatest since its discovery there. With a wingspan of 24 to 28 millimetres, females being larger than males, the Lulworth skipper is a small butterfly, the smallest member of the genus "Thymelicus" in Europe and among the smallest butterflies in Britain. Aside from the size difference, the sexes are distinguished by females having a distinct circle of golden marks on each forewing. Due to their likeness to the rays around the eye of a peacock's feather, these are often known as "sun-ray" markings, and they can faintly appear on males. The Lulworth skipper was first described by German entomologist
Lulworth Cove a natural arch. To the east there is a fossilised forest. Lulworth is also close to Kimmeridge, famous for its rocky shore and fossils. Oil-bearing sands beneath the sea bed form the largest British oil field outside the North Sea area, and contain the highest quality oil in Europe. Geologists and geographers have been interested in the area since the beginning of the 19th century, and in the 1830s the first serious study of the area took place. Since then the area has drawn students from all over the world. Purbeck suffers from trampling because of its many visitors and