Opalized ammonite fossils are some of the most unique and spectacular paleontological specimens. They were formed through a geological process known as opalization, wherein organic material from ...

Fossils found in the northern part of Hokkaido are a new type of ammonite, the once-ubiquitous spiral-shelled creatures that went extinct with the dinosaurs 65 million years ago, researchers said.

A giant fossil ammonite has been recovered from a fallen boulder on a beach. The edge of the creature's shell was spotted in the block by fossil collector Jack Wonfor on the Isle of Wight's ...