The Tyrant Lizard
Not much on this planet isn’t aware of the tyrannosaur. The largest and most powerful predator ever to walk the Earth, with its crushing teeth for daggers and eight tonnes of muscle, it is not only the most famous dinosaur, but also the most famous extinct animal overall. Even its whole fitting scientific name has become a household term, and the imaginations this superpredator has captured worldwide have come to life in an unbelievable amount of popular culture. It doesn’t really need an introduction. Of course, in a time where I finally illustrate the icons of the prehistoric Earth, I had to draw Tyrannosaurus rex again in a new light, almost a year after my last, though it might not look too different at a glance.
My old, less muscular tyrannosaur depiction from January, with Arnold Schwarzenegger for scale.
My current reconstruction in a newer, but replaced style.
Tyrannosaurus was one of the last dinosaurs alive in the Late Cretaceous period before their extinction, sixty-six million years ago. It ran riot in what would become western North America, which then was separated from the east by a great shallow sea called the Western Interior Seaway, and so was its own continent, Laramidia. To the north of its range was a lush, green, subtropical landscape of forests, floodplains and swampland, somewhat like today’s Everglades, intertwining with deltas to the nearby seaway. Here, the horned Triceratops was the most common meal on the menu, alongside the less common duck-billed Edmontosaurus and armoured Ankylosaurus. To the south on the other hand was a vast, dry fern savanna, dominated by the gigantic titanosaur Alamosaurus, which could grow to about twenty-six metres and forty tonnes, if not even more. The Late Cretaceous quite a different Earth. There was barely any grass, mostly only ferns that were a favourite meal for vegetarian dinosaurs. There were little-no ice caps at the poles, making the world a warm greenhouse, especially with the recent increase of volcanic activity. The Rocky Mountains nearby were also only starting to form, and their gradual formation would’ve seen the classic presence of stunning volcanoes in Tyrannosaurus’s domain, as seen in the artwork. But nevertheless this period also had some charming familiarities. Flowering plants (angiosperms) had started to evolve, alongside new insects such as bees to pollinate them. Though North America was split into two, the continents were already close to their modern forms. Mammals, stereotyped as living as little "shrews" under the shadows of the dinosaurs, were actually quite diverse at the same time, taking on weird yet quite familiar niches, such as the otter-like Didelphodon that lived in the swamps dominated by Tyrannosaurus. Some modern lineages of animals were also starting to evolve. Turtles and crocodilians swam the primordial swamps as they were millions of years before, as well as the first modern birds like waterfowl, such as the informally-named Styginetta, that was like a cross between a duck and a flamingo. The earliest known fossils of bats and penguins are already derived for their Paleogene days, so, alongside molecular evidence, it is plausible that even they were present sometime before the Cretaceous extinction, albeit in more primitive form.
Tyrannosaurus rex wreaking havoc in his swampland home. By Julio Lacerda.
As mentioned before, Tyrannosaurua was the largest known predator to walk the planet. The average tyrannosaur is estimated to have tipped the scales at about twelve metres and eight tonnes, already much larger than the typical elephant. The largest specimens discovered, such as Sue and Scotty, would’ve approached an even more massive ten tonnes. Not even that compares to the true hypothesised record-breaker however. A study from this year, based on allometry, has theorised that one outlier in a hundred-thousand tyrannosaurs would’ve been roughly a tremendous fifteen metres and fifteen tonnes! Other enormous theropods outscaling it in length, such as Spinosaurus and Giganotosaurus from the Middle Cretaceous, have been considered contenders for the title of largest terrestrial predator, but due to their slimmer builds were most likely lighter. We now know Tyrannosaurus was very bulky for a theropod, so it could attend these enormous weights.
Just to talk about its power as a predator even more, it had way more going for it. The tyrannosaur had one of the most powerful bites of the animal kingdom, able to crush bone with a blowing 35,000 to 57,000 newtons. These bones have even been preserved in the dinosaur’s coprolites or fossil faeces. Even its senses are very well-studied for a long-gone, ultimate predator. Unlike many other theropods, its eyes faced forward, giving it great depth perception up to six kilometres away, putting eagle eyes to shame. It also had large olfactory bulbs and nerves relative to the size of its brain, which implies it was great at smelling, like a bloodhound. Speaking of the brain, it is thought that tyrannosaurs were about as intelligent as crocodiles, which though not the smartest, do have remarkable strategies of intellect in hunting.
He sees you when you’re sleeping, he knows when you’re awake. Photo of Sue at the Field Museum of Natural History by Scott Robert Anselmo.
Tyrannosaurus transformed greatly as it grew. While the huge adult tyrannosaurs were slow, yet bulky and formidable and dealt with equally powerful quarry, the smaller youngsters were slimmer and faster with a probable coat of feathers (which would very well decrease as they grew), like ostriches on a killing spree, also hunting smaller lithe dinosaurs. This is called ontogenetic niche shifting, where a single species changes in lifestyle and ecological role as it grows into adulthood, seen in Komodo dragons today. It is somewhat like metamorphosis, though not as drastic. As a result, old and young tyrannosaurs are so different from each other they almost look like different species, and that was exactly what was mistaken by scientists, who once deemed the juveniles a separate genus: Nanotyrannus. Subsequent studies would soon classify them as nothing new, but just young tyrannosaurs. Still interesting though.
The life cycle of Tyrannosaurus. Note the change in build. By R. J. Palmer for the game Saurian.
Tyrannosaurus’s arms, being so comically small compared to its body, have always been popularly mocked as pathetic and useless, but even if they were mostly vestigial, they probably weren’t so useless entirely. Its arms were actually much stronger than a humans, and could basically bench press as much as 180 kilograms, the weight of a lion. There have been many theories proposed for their purpose, from holding on to partners while mating to pinning down prey. Even if there wasn’t a use, they still were nothing short of impressive in any way.
Just classic tyrannosaur arm mockery. Hilarious comic by Gary Larson.
Another popular culture cliché is having Tyrannosaurus roar at the top of its lungs in triumph, such as in blockbuster movies like Jurassic Park. This is so much depicted in a clear mammalian fashion, but this is unlikely for any dinosaur (save any mimicking bird, but those are really derived), since they are reptiles with different vocal organs. Though no vocal organ has been preserved for any tyrannosaur, it is thought that they sounded like distantly related crocodiles and ostriches. The earbones of Tyrannosaurus also seem to have been tuned for ends of the sonic spectrum we humans can’t hear, so it is plausible that they communicated with bone-vibrating infrasound just like them. This is not to say that dinosaurs didn’t "roar" in any way though, raspy and reptilian in particular. Crocodilians and cassowaries can occasionally raise a powerful, resonant voice that can be considered a roar, so I don’t think it’s implausible any dinosaur would’ve sounded quite like them, including Tyrannosaurus.
Now we’re onto the appearance of this reconstruction, which is shown here in detail in my reconstruction. The skin of tyrannosaurids are known by several impressions of small scales, similar to that of monitor lizards. I have a feeling they might be depicted a little too big here, but this was a sheet of paper I couldn’t zoom in on. Let’s say they’re just blurred representatives. Though not preserved, they are also thought to have had some feathers of a sort, plentiful in the chicks, but very sparse in the adults, similar to the hair of a modern elephant. It would overheat otherwise. If theropods were ancestrally feathered, which is what I lean to, then I think Tyrannosaurus itself would’ve been among the least, being so enormous and distant from birds. Here, you can only barely see them on the top of the neck.
One of the few tyrannosaur skin impressions, close up.
The faces of tyrannosaurs, based on osteological correlates, are now known to have been lined with keratinous hornlets on the top, probably for attracting mates which might’ve had varying hornlet length depending on the sex. I have depicted them here, speculatively extended a bit, essentially giving the "tyrant lizard king" its own crown. I chose this slightly countershaded black, ashen colour scheme (with mottled ashen patterns inspired by large lizards like marine iguanas and Komodo dragons), not only because I love how intimidating it is, giving that superpredatory vibe, but its also very natural-looking and could even help in camouflage in some cases, and may even reflect deadly ultraviolet radiation. You can also see a red, muscular dewlap right here, which in my original reconstruction was more like a saggy, fleshy wattle, which a lot even described to me as "melting." There’s actually an undescribed skin impression of the related Tarbosaurus/Tyrannosaurus bataar from Asia, which was interpreted in the 90s as being as part of a dewlap or even an inflatable, frigatebird-like sac from the throat, but unfortunately it has reportedly been poached and now lost, and it’s very possible it was not from the throat at all. Nevertheless, there are no other skin impressions from the throat of tyrannosaurids, and so it is acceptable speculation for them. The pose is slightly inspired by one of favourite artist Zdenek Burian’s famous paintings, and with all these colours combined, it might reminisce you of yet another depiction.
Familiar? From Walking With Dinosaurs.
“JESUS CHRICHTONOSAURUS GET THE FUKIRAPTOR OUT OF MY LAWN YOU FILTHY TRACHODONTS!” By Zdenek Burian.
My only gripe with this artwork is similar to another redesign I did with the Mikailodon, for the lineart of the head are inconsistently chunkier and blurrier compared to my other depictions. It’s probably a result from the difficulty of trying to take a good picture of the original drawing, which even then I had to adjust like I always do. It’s one of the problems of being a "tra-digital" artist you’ve been for almost three years and can’t leave. Nevertheless, I really loved working on this tyrannosaur, and I hope you enjoy it as well. Happy Fossil Day!
