If you have to smash your head all the time, you’d hope that your body had some mechanism to prevent your brain from rattling out. Knock that noggin around enough, and eventually (on evolutionary scales, that is), you might end up looking, well, very silly.
But scientists really wanted to understand how and why an animal could end up looking so silly. Specifically, they analysed the rounded skull of Moschops capensis, a silly-looking 3- to-5-metre-long mammalian ancestor from over 250 million years ago, with a particle accelerator in France. What they found was a “bony labyrinth,” to house soft parts and other adaptations that probably came from generations of regularly knocking heads. The new results might even require a re-orientation of some models of the fossils.
The key advance, the researchers explain in a post on The Conversation, came from combining data from CT scanning, which is sort of a complex x-ray, with synchrotron scanning. Essentially, there’s a particle accelerator in France called the European Synchrotron Radiation Facility. It sends electrons around a many-sided polygon, and every time they bend, they produce a beam of light down a long pipe. Researchers put their samples at the end of the pipe and used high-energy light to make images.
Image: Julien Benoit/PeerJ
These methods have “opened an entire new way of studying fossils, particularly what used to be ‘soft tissue’, like their brain,” study author Julien Benoit from the University of the Witwatersrand in South Africa writes in The Conversation. Plus, there are lots of other thick-skulled prehistoric creatures, so study of this skull could further elucidate headbutting dinos in general.
Through the high-tech imaging, the team found that Moschops' skull formed a helmet around its most important soft, brainy bits including its brain, inner ear, and some of its facial nerves, with bone on the top reaching 15 centimetres thick. They also imaged the architecture of the bony labyrinth—it looked as if the soft bits and the cavity they sat in was aligned to put the head in the optimal position during fights.
All of this implied to the researchers that the animal could have taken part in head-butting, as part of a social behavior similar to what goats and other head-butting animals might do today. It also shed light on other species—plenty of dinosaurs had thick skulls. But this in-depth study of the brain shows that the story goes much further than a thick skull. In fact, the new analysis may change the way scientists think about how this animal held its head, as shown below.
Left, how the AMNH has their Moschops skull aligned, and right, how it may actually have been held (Image: Julien Benoit/PeerJ)
Of course, the study involved a lot of informed speculation, since these animals lived more than 250 million years ago, and still some ambiguities as the researchers point out in their paper published yesterday in PeerJ. There are other animals with similar-looking brain cavities, and other hypotheses for what might be going on. More study is required to better understand the animal.