A stunning example of a highly pyritised ammonite fossil of the species Eteoderoceras (Eoderoceras) armatum from the world-famous Jurassic Coast beach of Charmouth, Dorset UK.
The fossil measures 120 mm (4.75 inches) across with matrix, which is absolutely huge for this species and about as big as they get. The matrix represents the crushed outer whorl of the ammonite, so it is the true size of the shell. The ammonite is well preserved with strong ribbing and suture lines and also has some of the much sought-after spines still preserved. There are also some smaller juvenile ammonite of the same species preserved in the matrix. It has a lovely metallic colour and shine. A beautiful, huge, and chunky fossil and a real on-off specimen.
These are very popular ammonites and examples like this are uncommon these days.
These Eteoderoceras ammonites are often called the "king of pyrites" as they are the largest and most impressive pyrite ammonites found on the Jurassic Coast.
Around 196 million years old, this fossil would make a wonderful addition to any collection.