E. rugosidens, specimen AMNH 5665|
Photo ©Shriram Rajagopalan from Vancouver, Canada
Please remember that these are hypotheses based on looking at fossils, the papers of others, and generally restating shown interpretations of the animal already distributed via film and screen and that we still have many unanswered questions about these very interesting animals. When traits like spikes and armor plating are highlighted everyone automatically (it seems) thinks of two possibilities: defense or mating. The defensive capabilities of nodosaurs like Edmontonia are fairly clear in looking at the skeleton and associate spikes and dermal plates: a large, but squat, animal with hardened scales on its back and large sharp protrusions of bone was probably very good at getting low and defending itself regardless of how it actually managed it. If its shoulder spikes were used as offensive weapons they were probably used mainly to intimidate as they would otherwise need to be picked up, moved with speed, and very accurately aimed. Any movement that elevated and sped up the body of this animal would have left the unprotected underbelly exposed long enough that it could have been tragic. This leaves us with two possibilities, as I see it: Edmontonia was much more turtle-like in its defense of itself or it was a brash and intimidating animal that attempted to scare away predatory dinosaurs rather than actually fight them. Both of these possibilities are intriguing and the behaviors behind both could be fascinating. Please feel free to discuss the likelihood of either or both scenarios. I enjoy these kinds of conversations and thoughts.