1.8" Jurassic Fossil Ammonite (Arnioceras) - United Kingdom

Jurassic Fossil Ammonite (Arnioceras) - United Kingdom #219953

This is a 1.8" wide ammonite (Arnioceras semicostatum) collected from North Yorkshire in the United Kingdom. The ammonite has been prepared mostly free of the rock it was found in and is Jurassic in age. One face is still partially covered by the rock the fossil was recovered from.

Ammonites were predatory cephalopod mollusks that resembled squids with spiral shells. They are more closely related to living octopuses, though their shells resemble that of nautilus species. True ammonites appeared in the fossil record about 240 million years ago during the Triassic Period. The last lineages disappeared 65 million years ago at the end of the Cretaceous.

What an ammonite would have looked like while alive.

More about ammonites