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.

The largest known species of ammonite is Parapuzosia seppenradensis from the Late ... has been sectioned into 'ammonite zones', where rocks in different areas can be associated with each other based ...

Based on the fossil record, ammonites came in a wide range of sizes and shapes, from smaller than an inch to as large as nine feet wide. Some ammonites had long, straight shells, while others had ...

Ammonite fossils, an example is shown here, are sea creatures that became extinct about 65 million years ago. Fossil remains have been found in rocks of all ages. Fossils of the simplest organisms ...