Superb illustrations by John Conway and Mark Witton got me thinking about those plates. Palaeontologists have put forward various ideas regarding their purpose, the most popular of which being thermoregulatory aids, display structures and defensive structures. In nature, structures often have multiple functions, with secondary functions being unrelated to their primary function. Feathers, for example, probably developed initially for insulation, but could have been easly modified for use in display, either through behavioral means or by changes in pigmentation. Structural modification of the feather - and other key anatomical features - then endowed the owner with an aerodynamic advantage.
That's a long-winded way of suggesting that Stegosaurus's plates probably did not perform one single function. Some of that's already been touched on in this earlier post, but I'm keen on the idea that part of Stegosaurus's display is concerned with how tall an individual looks, i.e., how much vertical space it occupies, especially in the eyes of potential mates, conspecific rivals and would-be predators. With fuzziness now known to be present in (some) ornithischians, I'm happy to speculate that some stegosaurs may have used stiff fur or 'fuzz' as it's often called, to extend the margins of the dorsal plates. Many palaeoartists, palaeoillustrators and palaeontographers already restore those dorsal plates with a sizable
|Stegosaurus stenops, displaying some serious fuzz. Not unlike a filthy old coconut husk. (Copyright © 2015 Gareth Monger)|
Next up: Yi qi (again).