The fossil record demonstrates a long history of interactions between predators and their prey from the Cambrian period onwards, showing for example that some predators drilled through the shells of bivalve and gastropod molluscs, while others ate these organisms by breaking their shells.  Among the Cambrian predators were invertebrates like the anomalocaridids with appendages suitable for grabbing prey, large compound eyes and jaws made of a hard material like that in the exoskeleton of an insect.  Some of the first fish to have jaws were the armoured and mainly predatory placoderms of the Silurian to Devonian periods, one of which, the 6 m (20 ft) Dunkleosteus, is considered the world's first vertebrate "superpredator", preying upon other predators. Insects developed the ability to fly in the Early Carboniferous or Late Devonian, enabling them among other things to escape from predators.  Among the largest predators that have ever lived were the theropod dinosaurs such as Tyrannosaurus from the Cretaceous period. They preyed upon herbivorous dinosaurs such as hadrosaurs, ceratopsians and ankylosaurs.