The find, made in 110-million-year-old deposits in northwest China, is of a new species known as Avimaia schweitzerae and the fossil has been described as "incredibly well preserved." The new species belongs to the group known as Enantiornithes, which were fairly common in the Cretaceous period, living alongside dinosaurs. However, the fossilized egg may have resulted in the death of the so-called mother bird, researchers said. "The egg shell consists of two layers instead of one as in normal healthy bird eggs, indicating the egg was retained too long inside the abdomen," Dr. Alida Bailleul said in comments obtained by...