353 — An unusual association of hadrosaur and therizinosaur tracks within Late Cretaceous rocks of Denali National Park, Alaska

I’m sitting in jury duty and they’re playing Jumanji 2 so loud I can’t see what I’m reading, so bear with me

This paper was published earlier this month in response to the discovery of co-occurring therizinosaur and hadrosaur tracks along the Cantwell Formation in Denali National Park. The tracks were laid on what is now a taller slope of the mountain, but it fell to where it was discovered. Though other blocks had prints from each of the two types of dinosaur, the largest block discovered had track from both.

It is possible to approximately identify the involved species by the placement of the digits, morphology, and the weight distribution of the prints (proxied by the depth of the tracks). Based upon the length and weight distribution, we can determine the age distribution of individuals as well, which tells us that the hadrosaurids’ age range was more narrow than usually seen tracks in this region.

Hadrosaurid and therizinosaurid tracks have never before been seen colocated like this in North America before (although it’s been seen before in Asia). But it begs the question of whether these two groups of dinosaurs actually coexisted, or if perhaps they passed by the same area within a short timespan. (The second seems a bit more likely.)