13" Tall Ammonite (Promicroceras) Cluster - Somerset, England

This is a spectacular 13" tall cluster of several hundred Lower Jurassic ammonites of the species Promicroceras marstonense. This ammonite-filled stone is quarried near Marston Magna, England, and is commonly referred to as "Marston Magna Marble". The piece has been meticulously prepared using mechanical tools to expose many of the individual ammonite fossils, a process that would have taken countless hours.

The block of stone measures 13 x 8 x 5" and weighs approximately 23 lbs. The base has been cut flat so that is stands up on a flat surface without the need for a stand. There are visible calcite seams running throughout the rock and calcite crystal-lined cavities visible on the sides. A really impressive display piece.

Ammonites were predatory mollusks that resembled a squid with a shell. These cephalopods had eyes, tentacles, and spiral shells. They are more closely related to a living octopus, though the shells resemble that of a nautilus. True ammonites appeared in the fossil record about 240 million years ago. The last lineages disappeared 65 million years ago at the end of the Cretaceous.

What an ammonite would have looked like while alive.
What an ammonite would have looked like while alive.
Promicroceras marstonense
Marston Magna, Somerset, England
Lower Lias, Obtusum Zone
13 x 8 x 5", 23 lbs
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