Protoceratops socio-sexual signalling again

It’s Protoceratops time again (hooray!). I have now published half a dozen papers about (or at least with a healthy dose of) Protoceratops andrewsi and a large part of that is because of the high number of really well-preserved specimens which make it one of the best dinosaurs to work on. There’s young juveniles through to large adults, large numbers of skulls and even skeletons, and all from a very narrow time and space that make it near enough (in palaeontological terms) a single population.

Among other things, I’ve used this to look at the growth and development of the frill and the implications for this major bit of dinosaurian anatomy being linked to sexual selection and dominance signals. (Here’s a recent round-up I did of all this work). The new paper out today is led by my former PhD student Andy Knapp and takes this previous simple work that only examined a few simple linear measurements and turns it up to 11.

Andy got to see almost every good Protoceratops skull going, including trips to New York, Warsaw and Mongolia to see material. Taking numerous photos of each allowed him to build 3D photogrammetry models of them and then get going with some quality morphometrics and analyses to look at how the skull changes in shape as the animals grow. It also shows that the skull can be divided up into distinct units and that these are somewhat independent of each other in their changes to size and shape and suggests evolution could act on each separately. The frill, rather inevitably, turned out to be a single unit and one that changed the most and one that is the most variable.

This fits very nicely with the prediction that the frill is used as a socio-sexual signal and if it’s true for Protoceratops then it’s probably true of other ceratopsians as well. I’d also suggest that this is good as we get very similar results from this very intensive and complicated methodology as we did from taking a few simple measurements of the skull and that gives some confidence that for future studies, the much quicker and easier methods may be more than sufficient to determine what kind of growth patterns are at play. There’s inevitably some more nuance and detail in the paper but happily this is another fully Open Access one, so click on this link here to be transported to a magical world of colourful ceratopsian skull bits in 3D.

I’ll finish here, but obviously huge congratulations to Andy on his great work on this long and complicated project and on getting an important paper out of it. I should also thank the Jurassic Foundation who gave Andy a grant to help with his travel and work on this project.

Knapp, A., Knell, & Hone, D.W.E.2021. Three-dimensional geometric morphometric analysis of the skull of Protoceratops andrewsi supports a socio-sexual signalling role for the ceratopsian frill. Proceedings of the Royal Society, Series B.