6.1" Calcite-Replaced Ammonite (Aegasteroceras) Cluster - England

This is an absolutely beautiful ammonite fossil cluster from the Conesby Quarry near Scunthorpe in North Lincolnshire, England. It's Lower Jurassic in age, or approximately 200 million years old. The ammonites are of the species Aegasteroceras sagittarium and the largest measures 3.4" wide. The shells of the ammonites were naturally replaced by calcite. A fossil oyster can be found exposed from the rock along the edge of the specimen. The base of the rock has been cut flat for aesthetic presentation of the ammonites without the need for a display stand.

There is some restoration to the bottom ammonite, located in the 2 - 3 o'clock area.

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.
Aegasteroceras sagittarium
Conesby Quarry, Scunthorpe, North Lincolnshire, England
Frodingham Ironstone, Obtusum Zone
Largest ammonite: 3.4" wide, entire specimen: 6.1 x 4.85"
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