End of an Era

Part of the Dinosaurs: Ancient Fossils, New Discoveries exhibition.

Our view of the mass extinction 65 million years ago is somewhat hazy, thanks to the unavoidable limitations of the fossil record. Yet there's no doubt that all nonavian dinosaurs went extinct. No fossils of nonavian dinosaurs have been found that are younger than 65 million years old.

Among the Last to Go

The family of dinosaurs known as ankylosaurs were covered in plates of armor, which protected the animals and helped them to recognize members of their own species. Ankylosaurs were one of the last known groups of nonavian dinosaurs.

Another Mysterious Extinction?

The wooly mammoth, saber-toothed tiger and giant ground sloth lived more than 60 million years after the last T. rex. But like nonavian dinosaurs, these animals also went extinct suddenly. Why?

Scientists aren't certain about what caused this more recent extinction, which took place around 11,000 years ago. Did humans overhunt these large mammals? Did disease wipe them out? Or is climate change at the end of the Ice Age to blame? Researchers continue to investigate.

Extinctions in Modern Times

Figuring out exactly why an animal went extinct is difficult--even when the event is recent. The California condor nearly died out: In 1985, only one breeding pair lived in the wild. What nearly wiped out these large scavenger birds that once lived across North America?

A wide range of factors has been blamed, from hunting to power lines to climate change over the last 10,000 years--and all probably played a part. Fortunately, condor numbers are now rising, thanks to captive breeding programs and efforts to reintroduce these birds into the wild.