2022 $1 Australian Dinosaurs Limited Edition 'DINO' Privy Mark 4 Coin PNCThe Australian Dinosaurs postal numismatic cover features four dinosaurs of the Cretaceous Period (145 million to 66 million years ago) when present day Australia was joined to Antarctica, New Zealand and South America to form the supercontinent of Gondwana. Being located further south than today, Australia had a cool, wet climate and vast floodplains covered about a third of what is now central Australia, providing an ideal habitat for dinosaurs.