Interesting, although Tyrannosaurus' bite could crush just about anything. No need for the shaking. We know that a Triceratops survived a Tyrannosaurus bit to the frill, but a hadrosaur was killed with a bite to the roof of the hip.

Interesting theory. Is it based mainly on head structures of prey?

I have never heard of that theory before. Can you point me to the research?

I hope it was everything you hoped it would be.

@@palaeo_channel ankylosaurus lived 90 to 65 million years ago

@@alexandercolon941 The specimens of Ankylosaurus have been found in the Hell Creek, Lance, Ferris, Scollard, and Frenchman Formations of North America in rocks that are aged 68-66 million years ago. If you have news of older find, I would like to know.

@@palaeo_channel 65 million years ago not 66 million years ago😏

@@alexandercolon941 In 1991, the International Commission on Stratigraphy defined the end of the Cretaceous by a golden spike in Tunisia dated 66.0 mya.

Its part of their evolution. It started at ROUGHTLY the same time as Jurassic Park that the reptiles to birds really took of. Before Jurassic Park, Dinosaurs were usually seen as slow, lumbering cold blooded creatures that dragged their tails (See the land before time). Jurassic Park, with its warm blooded creatures, really cemented the idea that they could move fast, and on two legs.

@@SImrobert2001 Disagree. I think Dinosaurs became warm blooded real early, at least during the Triassic. In fact, the very early thecodonts were likely warm-blooded, IMO. {Thecodonts were at the end of the Permian, two-legged, and I think possibly warm blooded already.} But, whether early or late Triassic, that process was done before the Jurassic. I still maintain that the Dinosaurs were a class by the Jurassic, at least. And that the Avian class was to evolve from them shortly thereafter.

@@craigkdillon I was talking about public perception. The public PERCEPTION changed.

I admit that I found evidence of intraspecies use of tail clubs after I made this video, or I would have mentioned it. I also think that this was probably not the primary use of the club. Intraspecific weapons are usually present when there are many individuals and resources (food, territory, mates, etc.) are scarce. There seem to have been very few Ankylosaurs in its area. Also males fighting for mates I find dubious with no examples without the weapons (supposedly females). Tyrannosaurus had a bone-crunching bite that even an Ankylosaurus’ armour could not stand up to forever. I think the club evolved as an offensive answer to tyrannosaurs, and that if one managed to get in one bite, they certainly were not getting a second. Using it against other Ankylosaurs would be expected if a disagreement developed. There are also signs that more ankylosaurs increased other herbivorous populations. It seems that predators wanted to stay away from these dinosaurs.

@@palaeo_channel No criticism of your really good video intended, I view ankylosaurs in the same way I view glyptodonts, and that is that they developed their traits through sexual selection, and not as a defensive counter to predation. If as in hedgehogs and porcupines this sexually selected trait, also deters predation, that is a welcome benefit, but not the main driver of the trait. Other notable sexually selected traits, being the peacocks tail, not used as a predatory deterrent. The horn of rhinoceros, although useful against predators as a byproduct , is primarily used against members of its own species. Almost all horned animals today, use those horns in mating rights conflicts, and these horns are seldom used against predators.

You could be right. Finding out the uses for anatomical features of extinct animals is difficult, even more for their primary use. I still think that the club was primarily defensive for the reasons I gave, but that might change with more information.

Triceratops was actually the most common herbivore at that time. It and Edmontosaurus were the top Tyrannosaurus food items. There is evidence of Triceratops surviving attacks and being eaten. Despite the force of a Tyrannosaurus bite, Ankylosaurus was very well defended. All its armour had to do was fed off one bite, because that club would make sure there would be no second.

I didn’t mean to imply that Dracorex and Stygimoloch weren’t valid (although they do look a bit dubious). There were so many dinosaurs in Ankylosaurus formations that I left out many that only have a few examples, like these two. This is why I refer to troodontids and dromeosaurs as there are many species, but only a few examples of each. I will probably talk more about Dracorex and Stygimoloch if/when I do a video on Pachycephalosaurus.

My definition of chew is the grinding of teeth along a horizontal plane. All living animals that grind their teeth do this. David Norman demonstrated how Iguanodon (and other Ornithopods) did things differently. I go through this and more of David Norman’s work in my Iguanodon video.

Exceptionally preserved and mostly articulated nodosaurs have been found. These were relatives of Ankylosaurus that had a different armour arrangement and no tail club.

@@palaeo_channel Oh, I see. Thank you.

There was a superbly preserved nodosaurid called Borealopelta, that was found with all of its osteoderms in place, and some indication of colouration.

The head was a box of fused bone, the most armoured part of the animal with armoured eyelids, as I say in the video. Also, predators tend to be risk-averse. Why take a bite at the heavily armoured tank that can kill you while there are far more Triceratops and Edmontosaurus around. Those have Tirannosaurus feeding marks on them, but none have been found on an Ankylosaurus.

Tyrannosaurus