When one considers hulking beasts like polar bears and musk oxen, not to mention those terrifying king crabs, it’s easy to assume that everything is bigger in the Arctic. However, this is not the case with Nanuqsaurus hoglundi, a dino that has just recently been classified as a distinct new species. While still a member of the ferocious Tyrannosaurid family, this two-legged terror from the arctic circle is significantly smaller than its cousin T. Rex.
In their study published in the journal PLOS One, paleontologists Ronald Tykoski and Anthony Fiorillo say that N. hoglundi lived 70 million years ago and roamed north of the arctic circle. The dinosaur’s remains were adequately distinct from other Tyrannosaurids to deem it a new species. These results were based on only a few fragments of the dinosaurs skull and jawbone.
While an adult T. Rex would have weighed in at 7 or 8 tons, ABC affiliate WFAA-TV/Dallas reported that N. hoglundi would have only hit a mere mere 1,000 lbs. Similarly, while T. rex could stretch up to 40 ft long, N. hoglundi probably only made it to 25 ft long.
The runt of the family. Note N. hoglundi’s (A) relatively small size compared to its Tyrannosaurid cousins, including T. Rex (B). (Fiorillo AR / Tykoski RS)
So why was N. hoglundi so much smaller than its big bad cousins? It could have to do with how little food was available in its habitat. While this part of the world was far warmer than it is today during N. hoglundi‘s era, the extreme shifts in sunlight exposure at this latitude would have still kept food scarce.
“Conditions in this setting were relatively warm, but there were profound to extreme seasonal changes in light regime throughout the year that would have limited resource availability and produced substantial variance in temperatures,” said Fiorillo and Tykoski.
There is also the thought that N. hoglundi could have shrunk due to a form of island dwarfism. While its habitat was never isolated by water barriers, it was cut off by high mountains. Just as is the case for modern era island dwarfs, lower food availability could have favored a smaller body size in this northern Tyrannosaurid.
One issue scientists remain confused on is what the hell N. hoglundi was doing so far north. The clues are few and far between, so if you have any ideas, let us know in the comment section below.
Some researchers suspect certain dinosaurs we dig up are actually on the smaller end of a given species’ size range. Check out our coverage on how some of the dinos we’ve found may have still been growing at the time they bit the prehistoric dust.