It is possible that dinosaurs roamed the northern hemisphere millions of years before was previously believed.
by University of Wisconsin-Madison More than 200 million years ago, dinosaurs first appeared on Earth. How and when did they spread? When faced with fractured fossil records, paleontologists have been debating that subject for decades. According to the conventional wisdom, reptiles first appeared on the southern half of the ancient supercontinent Pangea, known as Gondwana, millions of years ago. Later, they spread to the northern half, known as Laurasia. With evidence indicating the reptiles were prevalent in the northern hemisphe...