Close to 66 million years ago, during spring in the Northern Hemisphere, a 6-mile-wide chunk of space rock slammed into our planet and set off the world’s fifth mass extinction.

Although the fifth mass extinction wiped out three-quarters of all species on Earth, each species-specific ecosystem survived. "It's a really interesting and slightly disquieting find.

The fifth mass extinction event, the Cretaceous-Paleogene (K-Pg) Extinction, transpired about 65 million years ago, famously causing the extinction of the dinosaurs.

In a new study published Thursday in the journal Science, researchers pieced together the chemical identity of the asteroid that fueled the planet’s fifth mass extinction event.

Scientists believe since 2010 we have entered the sixth period of mass extinction. CO2 emissions will change the lives of plants and animals in the next three to four decades.

The fifth mass extinction wiped out 96 percent of life on the planet, including the dinosaurs. A new article theorizes that we currently are witnessing Earth’s sixth mass extinction.

A Princeton geologist has endured decades of ridicule for arguing that the fifth extinction was caused not by an asteroid but by a series of colossal volcanic eruptions. But she’s reopened that ...

Unless climate change is curbed, Earth's oceans could see a mass extinction of marine life unlike anything the planet has seen for millions of years, according to a new study published Thursday.

The Last Extinction: The Real Science Behind the Death of the Dinosaurs Gerta Keller. Diversion, $32 (320p) ISBN 979-8-895-15046-7 ...

Paleontologist Ken Lacovara never expected to find critical fossil data in a New Jersey suburb—let alone info about the asteroid that killed the dinosaurs. His dig site is now a fossil park and ...

At the start of the Cretaceous Period, which began 145 million years ago, sharks were once again widely common and varied in the ancient seas, before experiencing their fifth mass extinction event.

A study reveals the chemical makeup of the Chicxulub asteroid that collided with Earth and resulted in the extinction of nearly all dinosaurs 66 million years ago.