A stunning example of a calcite ammonite fossil of the species Asteroceras obtusum from the world-famous Jurassic Coast beach of Lyme Regis, Dorset UK.
The piece of limestone matrix measures 150 mm (5.9 inches) across and the fossil ammonite measures 75 mm (2.92 inches) across. The ammonite is very well preserved and has been prepared out of the rock to reveal the whole shell including the distinctive ribbed keel.
The ribs are very finely defined, and the colour is beautiful and very unusual for these fossils: a mottled mix of brown and grey - these are very unusual colours for this species. Part of the edge of the shell is open, showing the beautiful internal calcite crystal that have grown inside the shell.
This one is very unusual as it has a geological fault line running through the shell. this formed during the fossilisation process as the rock was pulled apart by tectonic forces. This created a gap that calcite crystals grew inside creating a vein. This adds an interesting geological story to the fossil.
A great example of a popular species and impressive in the flesh. The fossil weighs 1465 grams and a cut flat base to allow it to stand freely on its own for display. Fossils like this make great display pieces and add a real focal interest to any shelf, not to mention being a great conversation piece!
Around 196 million years old (Sinemurian, Early Jurassic), this fossil would make a wonderful addition to any collection.