A stunning example of an ammonite fossil of the species Promicroceras planicosta from the world-famous Jurassic Coast beach of Lyme Regis, Dorset UK.
The piece of limestone matrix measures 95 mm (3.7 inches) wide and the fossil ammonite measures 27 mm (1.05 inch) across. The ammonite is well preserved and has been prepared out of the rock to reveal the whole shell. The outer whorl split when the rock was opened, revealing the intricate internal crystalline calcite structure. These crystals show a "dog tooth" structure with hundreds of tiny points facing into the shell. The ribs are very finely defined, and the colour is beautiful: a mix of browns. A great example of the species and impressive in the flesh. The fossil weighs 300 grams and has a cut flat base to allow it to stand freely on its own for display.
Around 196 million years old (Sinemurian, Early Jurassic), this fossil would make a wonderful addition to any collection.