Horn Park Quarry Ammonites

February 10, 2021


Photographer: Michela Meda
Summary Author: Michela Meda

The fossils seen above are ammonites from Horn Park Quarry, England. These relatives of the current nautilus thrived for about 140 million years in the Jurassic and Cretaceous Periods. Ammonites are characterized by a distinctive outer shell composed mainly of aragonite and conchiolin and internally divided by septa into different chambers filled with gas and liquid to control the animal's buoyancy. The animal itself occupied the final chamber. Horn Park Quarry was once a working quarry and is now the smallest National Nature Reserve in Britain. Photo taken December 13, 2020.