Dinosaur Mating Rituals _ Walking with Dinosaurs in HQ _ BBC Earth

The males have started to display. During this, they rock back on their tails to impress potential mates. Occasionally, fights break out. With creatures this size, the forces at work during these confrontations are colossal. Enough to shatter ribs and shake the ground. Victor wins the right to mate. A female is approached by a young male. She responds to his calls first by stamping. And then generating very low frequency mating calls. This so-called infrasound is too low for most animals to hear. However, he picks these signals up through the ground and responds by walking close to her, rubbing his body down hers. She shows she is receptive. Mating is a dangerous activity for the female. She is going to have to carry at least an extra 10 tons on her back. As she has grown older, the vertebrae over her hips have become fused and reinforced. To help her cope with this ordeal, after a few days the Diplodocus have calmed. The female feeds on the edge of the herd, but she is still not large enough to be immune from attack and she is unaware she is being watched. An Allosaurus knows she is vulnerable. The predators wait for her to become distanced from the herd, saved by the huge tail of a larger Diplodocus. She rejoins the herd with deep wounds on her side, but she will recover. Diplodocus can live for a hundred years, and above a certain size, they have no natural predators. Sauropods dominate the late Jurassic, and it will be millions of years before new dinosaur herbivores evolve to replace them. With their passing, life will never again be this large.