Last updated June 9, 2017 at 10:27 am
For some palaeontologists perhaps the saddest moment in recent history was when it was suggested that Tyrannosaurus rex, the King of the Dinosaurs, had the indignity of being covered in feathers and probably looked like a cross between a drag queen and a 10 tonne chook. With big, scary teeth.
Now those same palaeontologists can once again hold their heads high with the knowledge that their favourite dinosaur didn’t have feathers after all.
The problem has been emerging over the last couple of decades as remarkable fossils from around the world have shown that many small to medium size meat-eating dinosaurs (theropods) did indeed have a wide array of feathers covering their bodies and limbs. This was hardly surprising as other fossil evidence has been found that confirms that birds evolved from the theropod dinosaurs, so perhaps feathers actually predated the arrival of birds.
In fact feathers have been found on such a wide variety of theropods, it has been assumed that they all had them, even the mighty T. rex.
But maybe that’s not the case. A group of palaeontologists have presented a number of fossils of skin impressions, not only of T. rex, but also closely related, large tyrannosaurid dinosaurs including Albertosaurus, Daspletosaurus, Gorgosaurus and Tarbosaurus and there’s not a single feather to be seen. They did, however, note that there is good fossil evidence that smaller species of tyrannosaurids did have feathers.
In their paper published today in the journal Biology Letters the authors discuss why it is that the ancestors to the tyrannosaurs are known to have had feathers but the big meat-eaters appear to have lost them in favour of the more familiar scaly skin. The palaeontologists argue that this feather loss was most likely due to the large size of T. rex and his mates. In smaller theropods feathers are thought to have originally evolved to help trap body heat but, as the animals got bigger, their problem was getting rid of excess heat rather than trying to trap it, hence the feather loss.
So it looks like the makers of Jurassic World were right to stick to their guns and refuse to put feathers on their T. rex. It’s probably only a fluke that they got it right but this could be a rare example of Hollywood leading the science.
- Link to original research article: rsbl.royalsocietypublishing.org/content/13/6/20170092
