A fossil of a small tyrannosaur that lived 70 million years ago was recently discovered in northern Alaska. The pygmy dinosaur, called Nanuqsaurus hoglundi (which means “polar bear lizard”), is believed to be a close relative of Tyrannosaurus Rex.
N. hoglundi was much smaller than the T. Rex. Its skull measures 25 inches as compared to the T. Rex‘s 60-inch skull. Researchers have postulated that the pygmy tyrannosaur’s smaller stature was an adaptation to the cooler Arctic climate. Although the Arctic would have been much warmer in the Cretaceous Period than it is today, bouts of cold temperatures would have caused variations in the food supply.
Below is an illustration of the relative size of N. hoglundi (A) as compared to its larger cousin T. Rex (B and C). Although N. hoglundi was only about half the size of the T. Rex, it still was an impressive 23 feet from head to tail.