4.5" Polished Ammonite (Promicroceras) Slice - "Marston Magna Marble"

Polished Ammonite (Promicroceras) Slice - Marston Magna Marble #211371

This is a polished slice of rock containing many small ammonite fossils, often referred to as "Marston Magna Marble". The ammonites are of the species Promicroceras marstonense and are Lower Jurassic (~4.500 million years old) in age. This rock is quarried near Marston Magna, Somerset, England and by slicing and polishing it, the beautiful inner chamber detail of the ammonites can be seen.

Both sides of the specimen have been polished to a glossy finish.

Ammonites were predatory cephalopod mollusks that resembled squids with spiral shells. They are more closely related to living octopuses, though their shells resemble that of nautilus species. True ammonites appeared in the fossil record about 240 million years ago during the Triassic Period. The last lineages disappeared 65 million years ago at the end of the Cretaceous.

What an ammonite would have looked like while alive.