Among the fossil fish, a slender bone caught his eye — a bird from 105 million years ago, new to science

Kevin Petersen, a former curator of the Kronosaurus Korner fossil museum in Richmond, Queensland, was digging through a layer packed with fossil fish when a long, light-brown bone caught his eye. A week later, after rain, he found a second unfamiliar bone nearby. The first — a leg bone just 2.5 inches (64.5 millimetres) long — is now the defining specimen of Tenuicruris piscanexum, only the second bird species from the age of dinosaurs ever named from Australia, some 105 million years after it lived over a shallow inland sea. Because the bones were still locked in rock, scientists at Australia's ANSTO research centre scanned them with neutrons, taking 720 images over 22 hours, and palaeontologist Matt White of the University of New England built 3D models from the scans. The second bone, a fused foot bone, is the first of its kind reported from Cretaceous rocks anywhere in Australia. Before this, fewer than a dozen isolated Australian bird bones from that era had ever been reported. Visiting palaeontologist Dean Lomax called the finds 'exceptionally rare'.