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 102 mm (4 inches) across and the fossil ammonite measures 27 mm (1.06 inches) across. The ammonite is well preserved and has been prepared out of the rock to reveal the whole shell. It is also what is known as a "popped" ammonite, meaning it has popped from the rock to reveal the whole shell and the impression of the shell in the rock itself. It has part of the shell missing which is due to a bite from a predator that most likely resulted in the death of the animal. Research has suggested that these bite marks may have been caused by squid-like cephalopods that lived at the same time as these ammonites. The ribs are very finely defined, and the colour is beautiful: a mix of gold (from iron pyrites in the shell), grey and white. I have not seen this combination of colours on one of these fossils before. Another unique feature of this fossil is that when the shell is help up to the light, it becomes translucent and glows. A great example of the species and impressive in the flesh. The fossil weighs 185 grams and has a cut flat base to allow it to stand freely on its own for display, with or without the shell in place.
Around 196 million years old (Sinemurian, Early Jurassic), this fossil would make a wonderful addition to any collection.