Two of Earth’s five confirmed mass extinction events could have been caused by nearby supernova explosions stripping the planet’s ozone layer, a new study argues. Although the explanation has been ...

Life at the start of the Ordovician remained confined to the seas with new animals evolving in place of those that didn't survive the Cambrian. Chief among them were the squidlike nautiloids ...

However, in the Ordovician, the creatures were invertebrates, or organisms lacking a backbone, such as brachiopods, trilobites, and corals. These organisms were perfectly suited to survive in the warm ...

International scientists have uncovered the oldest known phosphatic stromatoporoid sponge, dating back approximately 480 ...

Late Ordovician Period - The Ordovician Period refers to the interval ... Mollusca, Pelecypoda ("clams, scallops, oysters, mussels") - Animals in the class pelecypoda are sluggish bottom-dwellers in ...

The Paleozoic era's Silurian period saw animals and plants finally emerge on land. But first there was a period of biological regrouping following the disastrous climax to the Ordovician.

but early land plants and animals making the transition from water to land were wiped out, along with armored fish and other marine species. A cataclysmic shift at the end of the Ordovician led to ...

Chinese and South Korean researchers jointly discovered the oldest known phosphatic stromatoporoid sponge fossil dating back ...