You are in the riverbanks of Australia, 106 million years ago.

The air in the early Cretaceous Australian forest was thick and humid, tasting of wet fern and warm mud. You froze behind the massive trunk of a conifer, your heart thumping against your ribs, after hearing deep, resonant hooting sounds, each like a foghorn mixed with a bird call.

They emerged from the treeline, a herd of at least a dozen Muttaburrasaurus, their brown and tan hides patterned to match the dappled light. The sheer size of them made me shrink back—each one was far larger than a car, maybe seven meters long, walking on their powerful hind legs. They weren't graceful, but they were immensely powerful.

The leader, a massive female with a prominent, hollow bony snout, stopped mere meters away. She raised her head, testing the air, her flat, beak-like mouth snapping at the ferns.