December 20, 2011 Enlarge Two radiations of ray-finned fishes (Actinopterygii), Carboniferous forms (facing left) and acanthomorph teleosts (facing right) underwent distinct cranial (feeding) and later postcranial (habitat) stages in trait diversification. Credit: (Photographs by Lauren Sallan and Matt Friedman). The history of evolution is periodically marked by explosions in biodiversity, as groups of species try […]

An artist’s impression of the dicynodont, a mammal-like reptile. PALAEONTOLOGISTS have found tantalising evidence that their hunch is right. Dicynodonts – the prehistoric mammal-like reptiles named because of their oversized tusks – did exist in Australia. Fossilised remains of the bull-sized herbivores, which roamed the Earth before dinosaurs, have been found on every continent including […]