More sketching from the Idaho Museum of Natural History! Have I mentioned lately how much I love living five minutes away from a natural history museum?
This one was inspired by a chat with Dr. L. J. Krumenacker at a recent museum event where we discussed the mobility range of Oryctodromeus tails (pro tip, if you come give a paleontology lecture at the museum I will badger you with weird questions afterward). Oryctos, like most ornithopods, had tails that were strongly reinforced with tendons, limiting up-down flexibility (so no, no tail-dragging hadrosaurs like you see in older art), but Dr. Krumenacker said these tendons didn't affect lateral movement. I was seeking to understand how it is that oryctos had tails longer than their bodies but lived in burrows only 25 centimeters in diameter, and I suspect they curled up rather like this.
If you'll notice, a little friend is peeking in to say hello; fossil orycto burrows have indeed been found with much smaller burrows off to the sides, strongly suggesting that mammals co-opted the tunnels like a Cretaceous apartment building.