TINY TYRANNOSAUR! Well, tiny for a Tyrannosaur.

A study published on March 12 in the journal PLOS ONE described Nanuqsaurus hoglundi, a very close cousin of Tyrannosaurus Rex which roamed the prehistoric Alaskan landscape. One of the study's authors, Anthony R. Fiorillo, explained to National Geographic why the creature may have been so small:

In N. hoglundi's day, northern Alaska—then part of an ancient subcontinent called Larimidia—had weather like modern-day Seattle: seasonally cold but not frigid. The dinosaur likely would have wandered in the valleys beneath majestic snow-capped peaks and hunted other dinosaurs, including a duck-billed species, amid towering sequoias and flower-studded coastal plains, said Fiorillo, who received funding from the National Geographic Society/Waitt Grants Program.

Unlike Seattle, though, the Arctic was still a rough place, with long periods of darkness and light, as well as distinct seasons in which food wasn't readily available. For instance, prey species likely would have exploded in number during the summer, but then fallen off in the dark winter, leaving predators with little to eat.

This lack of food may explain N. hoglundi's diminutive size, since a large animal can't survive on scarce resources, explained Fiorillo.

You can read the full study (including additional diagrams) on plosone.org.

Thanks to Slog-tipper mr. sudbury! Have a hot dinosaur news tip or question? Send it to dinosaurs@thestranger.com