Two 10-meter bird-buffaloes of 95 million years ago nest by the tidewater on a North Texas mudflat. They are genus Protohadros, a missing link between the iguanodontids and the hadrosaurids. In this image, they bellow a warning to the dusk-prowling theropods at the edge of the woods. Hadrosaurs nested in large colonies, and then cared for their young--a new evolutionary strategy adopted in the Mesozoic Era by dinosaurs, birds, and mammals.