Paleontologists, as well as people with grown-up jobs, have long argued about the mysterious cataclysm that caused dinosaurs to become extinct more than 200 years ago. Some argue that it was meteorific in nature; others, volcanistic. What are some of the more controversial theories behind the disappearance of these gentle giants?

• Dinosaurs began eating one another until only one massively obese dinosaur remained and detached from Earth's gravity to become frozen and brittle in the cold of space, thus forming the moon.

• They evolved ways to temporarily remove their bulky hides and survive in a climate more conducive to lightly furred mammals; they walk among us today as the Denver Broncos.

• Asteroid or comet-like object approximately 10 kilometres in width struck Earth just off what is now the Yucatán Peninsula approximately 65 million years ago, sending dense clouds of dust into the atmosphere that blocked the sun's rays, darkening and chilling Earth to a level that significantly impeded photosynthetic activity. Once the dust settled, lingering greenhouse gases caused global temperatures to skyrocket. These climatic extremes caused the extinction of more than 70 per cent of plant and animal species on Earth at this time, which in turn made dinosaurs so sad that they packed weather-beaten leather suitcases plastered with quaint travel stickers and boarded space steamers to Phobos.

• They got sick or something, I don't know. Go find Mommy.