Balloonosaurus rex, by Tina Gagliardo

*Balloonosaurus rex* is a close relative of *Tyrannosaurus rex*, living in the Cretaceous period about 68 million years ago. It had nearly the same skeleton as the *Tyrannosaurus rex*, though much smaller in scale. A fully grown adult was about the size of a chicken. Its diet was rich in rubber plants, predecessors of *Ficus elastica*, which provided the polyisoprene molecules needed for maintenance of its skin. Interestingly, *Balloonosaurus* lacked muscles and vasculature, and is thought to have maneuvered aerodynamically by localized changes in air pressure. Its extinction may have been due to changes in the atmosphere that occurred after the great asteroid impact at Chicxulub, Mexico, 66 million years ago.