Scientists sifted through a million years of volcanic ash in a remote cave, and found a forgotten evolutionary world

A study published in Alcheringa highlights an excavation at Moa Eggshell Cave near Waitomo on the North Island. A research team led by Trevor Worthy of Flinders University and Paul Scofield of the Canterbury Museum recovered a diverse collection of ancient bird and frog bones, perfectly preserved between two distinct layers of volcanic ash.

Moa Eggshell Cave is nearly 920 feet above a local stream that cut through the cave over thousands of years, exposing deep layers of sediment. The fossils were found sandwiched securely between two historical ash bands. The lower layer dates back 1.55 million years, while the upper layer formed about one million years ago, providing a clean geological window into the Early Pleistocene .