Robin wonders how brontosaurs had copulated and assumes that the male had made amorous songs similar to those of the giant tortoise today:

If brontosaurs had mated like elephants or hippos do today, the males’ penises would have been quite long.

Since the animals had heads like frogs, Robin assumes that they stayed in lakes with only the nostrils and eyes out of the water. Perhaps they had a forked tongue and occasionally chased a few flies. Certainly the female buried eggs in the ground, and the newly hatched offspring on the way to the pond were the meal for a few predators.

“Unfortunately, we’ll never know!” regrets Robin.