2.85" Iridescent Hoploscaphites Ammonite Fossil - Montana

This is a bumpy, 2.85" Hoploscaphities ammonite specimen collected from the Pierre Shale of Montana. The ammonite is excellent condition, considering the difficulty (and time required) to remove it from the rock. The shell has a red iridescence that enhances the natural texture and white coloring. The rock it was found in is shaped and cut flat for easy, aesthetic display.

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.

These 70 million year old ammonites lived when South Dakota was a shallow inland sea. It was found preserved in a concretion that was split open. It then had to be hand prepared to remove the hard rock surrounding it from the shell, a very time consuming task.
Hoploscaphities crassus
Garfield County, Montana
Pierre Shale - Baculites cf. eliasi Zone
Ammonite: 2.85" wide, Entire specimen: 3.4 x 3"
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