In the badlands of eastern Wyoming, the Lance Formation is a trove of prehistoric fossils. And one area in particular — a region less than 10 kilometers (6 miles) across — has provided scientists with ...

Some 66 million years ago, just before the great extinction, the duck-billed dinosaur Edmontosaurus annectens walks in the soft mud of a coastline passing the sun-dried a carcass of another individual ...

In 1980, Luis Alvarez and Walter Alvarez, who were looking at a clay layer, discovered an unusual increase in iridium. This was more than an anomaly in the trace of metal but was actually evidence of ...