The Most Useful Fossils in the World | Eons • PBS

Crocodiles, horseshoe crabs and tuatara are animals that have persisted for millions of years, said to have gone unchanged since the days of the dinosaurs. But even the most ancient-looking organisms show us that evolution is always at work. | Eons • PBS

For decades, one of the most abundant kinds of fossils on Earth, numbering in the millions of specimens, was a mystery to paleontologists. But geologists discovered that these mysterious fossils could basically be used to tell time in the deep past. | Eons • PBS

120K views · 3K reactions | How Whale Evolution Kind Of Sucked  | Eons • PBS | Facebook

54K views · 1.3K reactions | In order to understand where hearts came from, we have to go back to the earliest common ancestor of everything that has a heart. It took hundreds of millions of years, and countless different iterations of the same basic structure to lead to the heart that you have today. | Eons • PBS | Facebook