Tag Archives: Ammonites

Top Stories Tamfitronics The Cretaceous period ended with a bang 66 million years ago when an asteroid more than six miles across collided with the Earth off of the Yucatan Peninsula. The resulting prodigious environmental change to land, sea, and atmospheric habitats ultimately led to the famous extinction of the dinosaurs, but also sounded the death knell of other charismatic fossil groups such as ammonite mollusks.Ammonites are well known for their beautiful, pearlescent coiled shells, and had flourished in the Earth's oceans for much longer than the iconic dinosaurs, having originated more than 350 million years before their extinction.Ammonites basking under the Late Cretaceous sun. Artwork by Callum Pursall (@cpursall on X)Some paleontologists, however, have argued that the number of ammonite species, their diversity, was actually declining well before their extinction at the end of...