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A Diminutive New Tyrannosaur from the Top of the World

PEROT MUSEUM PALEONTOLOGISTS DISCOVER A NEW GENUS AND SPECIES OF A TYRANNOSAUR THAT ONCE ROAMED ANCIENT ARCTIC LANDS OF NORTHERN ALASKA

Nanuqsaurus hoglundi renderingILLUSTRATION BY KAREN CARR

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IN THE NEWS! The discovery of Nanuqsaurus hoglundi was featured in the "Top 100 Stories of 2014" by Discover! Our "pint-sized T. rex" is on the list with other amazing science stories of 2014 including comet landings, dwarf planets, major epidemics and more. Click here to see the article.

Tony Fiorillo, curator of earth sciences and paleontologist, and Ron Tykoski, fossil preparator and paleontologist, are at it again!  The two have just co-authored and published a new paper announcing a new genus and species of a tyrannosaur that once roamed the ancient Arctic lands of Northern Alaska!

This new animal has been formally named Nanuqsaurus hoglundi.  The first name honors the Iñupiat people whose traditional territory includes the land where these bones were found, and the second name is in honor of Dallas entrepreneur and philanthropist Forrest Hoglund, whose extraordinary leadership helped raise $185 million to build the new Perot Museum, which opened in late 2012.  The Nanuqsaurus, which loosely translates to “polar bear lizard,” is a pint-sized cousin to one of the most revered dinosaurs of them all – the Tyrannosaurus rex.

Relative size of Nanuqsaurus hoglundiSilhouettes showing approximate sizes of representative theropods. A, Nanuqsaurus hoglundi, based on holotype, DMNH 21461. B, Tyrannosaurus rex, based on FMNH PR2081. C, Tyrannosaurus rex, based on AMNH 5027. D, Daspletosaurus torosus, based on FMNH PR308; E, Albertosaurus sarcophagus, based on TMP 81.10.1; F, Troodon formosus, lower latitude individual based on multiple sources and size estimates; G, Troodon sp., North Slope individual based on extrapolation from measurements of multiple dental specimens [47]. Scale bar equals 1 m.

The scientific paper describing the find – entitled “A Diminutive New Tyrannosaur from the Top of the World” – has been posted on the prestigious science journal PLOS ONE, an international, peer-reviewed, open-access online journal that features reports on primary research from all scientific disciplines. To read their entire manuscript and view renderings, go to http://dx.plos.org/10.1371/journal.pone.0091287.

Alaska’s North Slope in the Prince Creek Formation

Fiorillo discovered what is now known as the Nanuqsaurus hoglundi in 2006 while excavating Alaska’s North Slope in the Prince Creek Formation.  The excavation site – about 13 x 13 feet in size -- is located almost 400 miles northwest of Fairbanks and many miles above the Arctic Circle on lands managed by the Bureau of Land Management.  The research was funded by the National Science Foundation Office of Polar Programs.      

While a typical adult T. rex might have been 40 feet in length and weighed 7-to-8 tons, Fiorillo and Tykoski estimate the diminutive yet fully grown Nanuqsaurus would be approximately 25 feet long and weigh 1,000 lbs. Fiorillo and Tykoski assert that the reduced stature might be attributed to Alaska’s ancient climate, the isolation of the area, and the limited food resources at the time.

“The North Slope was isolated by the Brooks Range, and with it being dark half the year, there probably wasn’t a lot of food up there.  Over time it would have become more advantageous for the Nanuqsaurus hoglundi to have a smaller body size,” said the authors. 

They added that examples of animals adapting for survival in isolated environments include the large mammoths stuck on a Russian Arctic coast island that evolved to the size of a cow and monitor lizards that tripled in size to become fierce Komodo dragons. 

“The ‘pygmy tyrannosaur’ alone is really cool because it tells us something about what the environment was like in the ancient Arctic,” said Fiorillo.  “But what makes this discovery even more exciting is that Nanuqsaurus hoglundi also tells us about the biological richness of the ancient polar world during a time when the Earth was very warm compared to today.”

Phylogenetic position of Nanuqsaurus hoglundi within Tyrannosauridae recovered from second phylogenetic test.Phylogenetic position of Nanuqsaurus hoglundi within Tyrannosauridae recovered from second phylogenetic test. Figure shows only the relationships within Tyrannosauridae. Thick bars indicate uncertainty of geological range for a given taxon. Numbers at nodes are Bremer support values for that clade. Open circle indicates node-defined clade name. Half-circle arc indicates a stem-defined lineage name.

FINDING A NEW GENUS AND SPECIES

The two paleontologists acknowledged they had a new genus and species – which happens rarely – after running analyses “every which way imaginable” and realizing the new animal didn’t match any of the tyrannosaur species known at the time.

Tykoski, who handled the meticulous preparation work amidst a dusty paleo lab in the Perot Museum’s Fair Park location, saw that he had pieces from a small but adult carnivore when he found the top of a skull section, the tooth-bearing front part of the lower jaw, and part of an upper jawbone of the face, called the maxilla.  What surprised him most was finding a section of the maxilla which showed distinctive sockets along its edge that are only present in adults of some advanced tyrannosaur species.

“I had worked almost a month on a block of rock about the size of a football,  whittling away 70 million years’ worth of sediment,” said Tykoski. “We knew we had an adult for a couple of reasons, the most prominent being when we saw the well-developed peg-in-socket edge of the bone, because that feature doesn’t emerge until an animal has reached maturity.”

As he extracted the various fossils, he and Fiorillo were puzzled, especially after finding sockets for two ridiculously small teeth in the front of the lower jaw – something of a surprise because most tyrannosaurs have larger teeth there. The two scientists also were taken aback when they saw the diminished size of the animal.

NAMED IN HONOR OF FORREST HOGLUND

Fiorillo and Tykoski decided Forrest Hoglund was an obvious choice for the naming because of his career working in science-related industries and his vast philanthropic efforts.  Also, Hoglund is credited with propelling the Perot Museum to exceed its $185-million campaign goal in November 2011, a full year before the museum building opened.

Trained as an engineer, Hoglund enjoyed a distinguished career in the natural gas industry, including many years in top management with Exxon, Texas Oil and Gas, and EOG Resources. He now serves as chairman of the board of Forest Oil Company and SeaOne Maritime Corporation. In addition to chairing the Perot Museum capital campaign with which his family’s Hoglund Foundation contributed $10 million, Hoglund collectively raised almost a billion dollars over the past decade for the Houston Museum of Natural Science; Reasoning Mind, an innovative math-education program; and the University of Kansas, to name a few. 

“By naming Nanuqsaurus hoglundi in honor of Forrest, we’re also paying tribute to him and the Hoglund family for being the Perot Museum’s biggest cheerleaders, one of our most generous donors, and for Forrest being one of the best fundraisers ever!” said Nicole G. Small, Eugene McDermott chief executive officer.

“Nearing my 81st birthday, I’ve been called an old dinosaur a number of times in my life, but I guess now the name fits,” said Hoglund, whose broad appeal is partly due to his contagious sense of humor. “On a serious note, I’m deeply honored to have the Nanuqsaurus hoglundi named for me and my family’s work on behalf of the Perot Museum.”

MORE TO COME!

Fiorillo notes that the North Slope quarry is the same location he and Tykoski made other discoveries, including a new horned dinosaur species called Pachyrhinosaurs  perotorum announced in 2011 and part of a juvenile Pachyrhinosaurus perotorum described in 2013.

“I find it absolutely thrilling that there is another new dinosaur found in the polar region,” said Fiorillo.  “It tells us that the ecosystem of ancient Arctic was a very different place, and it challenges everything we know about dinosaurs.”

Fiorillo and Tykoski’s work will continue in that region.  From the 2006 excavation, Fiorillo brought back jackets containing 6 tons of rock – and only a fraction of that has been examined.

“We’re at the tip of the iceberg, to use a pun, as far as our exploration goes of the polar region,” said Fiorillo.  “There’s still a lot of work to do, and that’s something to which we very much look forward.”