Scientists have identified a giant salamanderlike predator with sharp fangs that likely ruled waters 280 million years ago. The creature existed before the dinosaurs and likely used its wide, flat head to suck in prey. Findings were published Wednesday in the journal Nature. Researchers study such creatures to understand the origins of tetrapods, four-legged animals that clambered onto land with fingers instead of fins and evolved to birds, amphibians and humans. The discovery was in what’s now Namibia in Africa. That area was once encrusted with glaciers and ice, hinting that tetrapods thrived in colder climates much earlier than previously thought.