Let’s try something together, ok? Open Google Images and search for “Gorgosaurus”. Now count how many results are blue or bluish. Quite a few, uh? Just as Carnotaurus is red, Gorgosaurus is blue. But where did this meme come from?
The first blue Gorgosaurus we managed to find in media was the one that appeared in the anime Dinosaur King (2007-2009) and the related trading card game and arcade and Nintendo DS videogames. The colour reminds of a 1996 illustration by Canadian paleoartist Michael Skrepnick (from archive.org). Like most Dinosaur King models, it’s surprisingly accurate for coming from an anime where dinosaurs breathe fire or cast lightning at each other, and Gorgosaurus is clearly recognizable.
But undoubtely the trope codifier is Walking with Dinosaurs 3D (2013). In this movie, the main antagonist of Patchi the Pachyrhinosaurus is Gorgon, a Gorgosaurus with a beautiful iridescent blue colour.
When the movie was released there were three Gorgon models made by by Vivid Toys (a miniature, a 20 cm articulated model, and an articulated model more than 50 cm long), and two cup toppers (probably both from) Golden Link. Not only the movie helped spread the notoriety of Gorgosaurus, but also sprouted various similar-looking works.
Like Jurassic World: Alive (and Android and Iphone game akin Pokemon Go!), where we find a Gorgosaurus cleary related with Gorgon from Walking with Dinosaurs 3D. May it be the reason why it’s one of the best restorations in the entire game?
And then we’re at the Beasts of the Mesozoic model (Creative Beast Studio, 2024). The color is based on the blue subspecies of the racer snake, Coluber constrictor foxii. It shares the same body of Albertosaurus, Daspletosaurus, and Tarbosaurus, with only the head and neck being different. Putting them side to side, it’s clear that the base was Tarbosaurus (another hint is the forelimbs, the smallest among Tyrannosauridae): not exactly a perfect choice for Gorgosaurus, given that this genus and Albertosaurus had different proportions from most Tyrannosauridae, especially in the longer hind limbs (click here to see a comparison). The head sculpt reference was GetAwayTrike’s restoration, itself based upon CMN 2120 (holotype of Gorgosaurus) with some details from UALVP 10 and AMNH 5458. While the skull profile of the BOTM model is flawless, when seen from above it’s considerably narrower than it should be. This could be due to technical issues or using an immature Gorgosaurus specimen as a reference.
The model features 22 points of articulation, some improvements when compared to the previous Tyrannosaurs: there is an additional segment in the tail (raising the total number to four), which increases its flexibility; the torso joint was improved and now the animal can bend forward or upwards; But, above all, the neck mobility is now way better, finally allowing the head to look downwards. So yes, your Gorgosaurus can look down at a BOTM Monoclonius or Mattel Jurassic Park character, as it should be! Of course, the most striking feature of this model is its metallic blue sheen. But how much science is there behind it?
Among vertebrates, skin colour comes from chemical phenomena and physical phenomena. In the first case, pigments are found inside by specialized skin cells that go by the name of chromatophores. In birds they are located in the epidermis (upper layer of the skin), while in reptiles they are located in the dermis (a deeper layer).
Structural colourationì, on the other hand, depends upon a physical phenomenon: the microscopic structure of the skin interferes with the light, altering its direction. Using the color blue as an example, in modern birds, it appears when a light ray A (which is white, but because is composed of all the rainbow colors) mets air-filled spaces between the keratinous layer on the surface of the barbules C (the smallest unit of a feather) and the underlying chromatophores B, breaks down just as passing through a prism, and the short wavelength, the one corresponding to blue, is mirrored outwards E, while the other colors D, with longer wavelengths, pass through the layer and get absorbed by the chromatophores. Therefore, the feathers of some birds look blue, even if the pigments they contain may be brown!
Iridescence (i.e. the phenomenon whereby the feathers of some birds may appear blue, green, or purple, depending on the angle from which they are observed) happens due to the presence of two layers of reflective particles, one on top of the other (C and F), with different refractive indexes. Light meets them and gets mirrored back exactly as explained above but, since the light mirrored from the bottom layer has a slight delay (G), the two reflections are out of sync. The light beams that are created, therefore, interact with each other, and so certain colors are amplified or attenuated. Varying the angle at which the rays meet again (and therefore our eyes see them), the color we see also varies.
But wait, there’s more! So far we talked about feathers. Which are, after all, complex structures, made up of finely woven barbules. Maybe the dinosaurs’ scales weren’t able to achieve the same results? Well, in mammals’ fur, there are only melanosomes (responsible for various degrees of orange, brown, and black), and so they’re not the most colorful animals, but reptiles possess other types of organelles, too: xanthophores and erythrophores, which gives bright reds and yellows, and iridophores, which contain reflective crystals, which interfere with light. As mentioned above, blue colors may be obtained thanks to interference. Some mammals are blue colors despite lacking iridophores thanks to this phenomenon (it also works for the eyes of blue-eyed people): the bright blue of the mandrill snout, for example, comes from the interference between layers of collagen fibers in the dermis (do you remember? It is a layer of skin deeper than the epidermis), which akin to bird feathers reflect blue. Interestingly, the exact same process evolved in birds with blue skin (not feathers), such as cassowaries. Iridescent coloring is not particularly expensive to produce (Meadows et al. 2009), quindi non è così improbabile da un punto di vista biologico neanche per un teropode da otto metri.
BIBLIOGRAPHY:
Doucet S.M. Meadows M.G. (2009) Iridescence: a functional perspective. Journal of the Royal Society Interface. 6S115–S132
KF Liem, WE Bemis, WF Walker, L Grande (2000) Anatomia Functional Anatomy of the Vertebrates: An Evolutionary Perspective. Brooks Cole edition. 784 pp.
Meadows M.G., Butler M.W., Morehouse N.I., Taylor L.A., Toomey M.B., McGraw K.J., Rutowski R.L. (2009) Iridescence: views from many angles. Journal of the Royal Society Interface. 6S107–S113
Prum R.O. (1998) The anatomy and physics of avian structural colours. Proceedings of the 22nd International Ornithological Congress, 1633-1653
Prum R.O., Torres R.H. (2004). Structural colouration of mammalian skin: Convergent evolution of coherently scattering dermal collagen arrays. Journal of Experimental Biology. 207 (12): 2157–2172
Voris J.T.; Zelenitsky D.K.; Therrien F.; Ridgely, R.C.; Currie P.J.; Witmer L.M. (2022) Two exceptionally preserved juvenile specimens of Gorgosaurus libratus (Tyrannosauridae, Albertosaurinae) provide new insight into the timing of ontogenetic changes in tyrannosaurids. Journal of Vertebrate Paleontology, 41:6, DOI: 10.1080/02724634.2021.2041651
www.deviantart.com/getawaytrike/art/Balanced-dreadfulness-713705398
The author thanks Ivan Ioffrida and Fabio Manucci for their help in writing this article.