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 122 mm (4.8 inches) across and the fossil ammonite measures 25 mm (1 inch). The ammonite is very well preserved and has been prepared out of the rock to reveal the shell. The ribs are finely defined, and the yellow colour is beautiful. It is a rare example that has some bright iridescence on part of the outer whorl. This area flashes bright green and orange as the angle you view it from changes. This is hard to capture in a photograph and it looks much more vivid in real life! The iridescence is caused by a small amount of the original aragonite shell layer being preserved against the yellow calcite crystals. Iridescent ammonites from the Jurassic Coast are very sought after.
A great example of the species and impressive in the flesh. The fossil weighs 662 grams and has a cut flat base to allow it to stand freely for display.
Around 196 million years old (Sinemurian, Early Jurassic), this fossil would make a wonderful addition to any collection.