Ancient Bird Fossil Has Unlaid Egg Inside Unlisted Video

According to Sciencemag.org, "For the first time, researchers have found an unlaid egg inside a fossil bird. The find—belonging to a sparrow-size flyer that lived in northwestern China 110 million years ago—is especially remarkable because fully formed eggs typically only stay within an adult bird for about 24 hours." This discovery initially puzzled researchers, they didn't know the unusual, squashed mass within the headless fossil’s abdomen was actually an egg.