Mortal Combat in the Mesozoic II

The best defense is a good offense

Plant eaters are dangerous. One of the most widespread and dangerous misconceptions about nature is that animals that eat plants are not capable of violence. In fact, some herbivores seem to have evolved to be dangerous as a survival strategy. In the last installment of Mortal Combat we talked about how an individual of the plant eating dinosaur Protoceratops used its garden-shear jaws as a weapon during a life and death struggle with a Velociraptor. Today, we will talk about a dinosaur that took things a step further, evolving structures that would have served primarily as biological weapons in the struggle for survival.

Stegosaurus has always been my favorite dinosaur. I love the spiked tail and the row of plates. A formative early experience with Stegosaurus is its depiction in Fantasia, where we see a Stegosaurus fight a carnivorous dinosaur to the death in a dramatic scene. The fossil record tells us that this fictional scene may be close to reality.

Above: Mounted skeleton of Stegosaurus stenops from the Morrison Formation (Upper Jurassic) of Wyoming. Note the enlarged, spike-like osteoderms on the tail. Image from Maidment SCR, Brassey C, Barrett PM (2015). doi:10.1371/journal.pone.0138352. No changes made, used under the following License.