4" Placenticeras Ammonite

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Quick Overview
We were fortunate to have an exceptional collection of Ammonites to come back to us. This rare Placernticeras Ammonite from South Dakota displays extremely well developed and very distinct suture patterns. The specimen is nicely nestled in its natural matrix and is easily displayed. An excellent, museum grade specimen, complimenting any collection.
More Information
Measurement in matrix: ~ 5-1/2" x 5" x 3" Ammonite measurement: ~ 4-1/8" across Location: South Dakota State, USA Time period: Cretaceous ~ 95 myo

Ammonites are an extinct group of marine animals in the Cephalopoda class. They are invertebrates and are more closely related to coleoids (squids, octopus, and cuttlefish) than they were to the chambered nautilus, even though they looked much more similar to the later.

The name Ammonite was derived from "ammonis cornua," translated to mean Horns of Ammon. Ammon was an Egyptian god that was typically depicted wearing ram horns, whose spiraled shape is similar to that of an Ammonite.

Ammonites first appeared in the oceans during the Devonian Period, some 400 million years ago. They died out around 65.5 million years ago along with the dinosaurs.