This 110-Million-Year-Old Armored Dinosaur Was Turned To Stone By A Geological Medusa


Robin Andrews

Science & Policy Writer

The nodosaur and its terrifying armor plating. Robert Clark/National Geographic.

Dinosaur fossils come in many forms, but most of them are incomplete skeletons. With some exceptions, large sections of these long-lost beasties have disintegrated or are otherwise lost to time – it takes a certain level of geological serendipity to find anything more.

It does happen, though. A few months ago, for the first time, the fossilized brain of a non-avian dinosaur was found, something only made possible because the swamp the creature died in “pickled” its brain. Now, as has been dramatically revealed by National Geographic in its June 2017 edition, a 110-million-year-old nodosaur, an armored herbivore, has been found with half of its skin and armor intact.


Easily, this is one of the best preserved dinosaurs to ever have been found. Uncovered from a mine in Alberta, Canada, researchers were stunned to find that its armor plating was still so strong after all this time that the heavy-equipment operator that accidentally struck it failed to cause any significant damage.

Far from being a fragmented mess, this nodosaur – still covered in its ultra-rigid keratin sheaths and its mineralized skin – has been fossilized and preserved in true 3D.


Weirdly, this landlocked monster was found in a small “impact crater” within a deep-sea sediment layer, somewhere it never would have dared to venture back during the Early Cretaceous. Indeed, this geographic displacement explains why it was so well-preserved in the first place.

Back then, Canada was a very different place. North America was segregated between West and East, with the Western Interior Seaway and the Hudson Seaway forming a somewhat shallow Y-shaped ocean. This particular nodosaur probably lived along the coastline, and had a great time munching on as many leaves as it liked.


Something unfortunate befell it, however, and it died, falling into the coastal waters and drifting out to sea. Eventually, it arrived in the ocean, by which point it would have started to decompose quite quickly.

Had it been still on land or even in shallow coastal waters, its armored skin would have been lost to time. Fortunately for paleontologists, something rather disgusting took place.

The bacteria breaking down its organic components were expelling quite a lot of gas as they did so. This caused the body to swell up and become buoyant enough to float far out into the middle of the ocean. At some point, it burst, which caused it to sink to the seafloor.

Its collision with the sediment down there created a small crater, which was then soon covered by a layer of mud that prevented any oxygen – or hungry bottom-feeders – from getting to it, which inhibited both chemical and physical decomposition. Increasingly compacted by the layers of sediment above, it began to mineralize rather than break down.


It became petrified, as if it had caught the gaze of Medusa herself.

To say this is an unprecedented find would be quite the understatement. Now on display at the Royal Tyrrell Museum of Paleontology in Alberta, it looks more like a statue than a real fossil. Although it’s now lacking in any distinct color, the chemicals trapped in its mineralized skin suggests it may have once been reddish in color.

Its keratin plating was perfectly preserved. Robert Clark/National Geographic.

“I feel like this is the most impressive fossil I have ever seen,” Franzi Sattler, a palaeontologist specializing in evolutionary biology and biodiversity from the Free University of Berlin who was not involved in the project, told IFLScience.

“As paleontologists we get to see all kinds of vertebrate and invertebrate fossils in various states of preservation. It is very common to even see bones in different colors,” Sattler added. “But this is not just bones, it is a view of a dinosaur as it would have been when it was alive.”


“I can only imagine how exciting it would be to work on this specimen. It's beautiful!”

Around 5.5 meters (18 feet) long and weighing at least 1.1 tonnes (2,500 pounds), this four-legged, rather stout dinosaur is setting all kinds of records aside from its immaculate preservation. It’s the oldest dinosaur that has been excavated in the region, and it belongs to not just its own species, but its own genus, a higher biological “class”.

Armored though it may be, this fossil was still somewhat fragile when it was first dug out of the oil sands of Alberta. It took a team led by the museum’s fossil preparator Mark Mitchell more than 7,000 hours over the past five years to fully expose the nodosaur’s skin, bones, and armor.

The story doesn’t end here, however. The team are still working on their official paper, and as part of their research, they’ll be scanning the petrified dinosaur to see what its internal organs looked like. In fact, because the mineralization of the skin happened so quickly, there’s a chance that some of its organs may still be partially intact.


Watch this space.

The story appears in the June 2017 edition of National Geographic.


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