6.2" Ammonite (Promicroceras) Cluster - Marston Magna, England

This is a 6.2" tall stone containing many small ammonite fossils. The ammonites are of the species Promicroceras marstonense and are Lower Jurassic (~200 million years old) in age. This rock is quarried near Marston Magna, Somerset, England. Locally this ammonite filled rock is known as "Marston Marble". There are calcite crystals lining both sides of the face of the specimen.

The piece has been painstakingly prepared with mechanical tools to expose all of the individual ammonite fossils on one side. The base of the specimen is cut flat to stand unassisted.

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.
$395 $300
Promicroceras marstonense
Marston Magna, Somerset, England
Obtusum Zone
Rock: 6.2 x 5", up to 3.2" thick
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