Tyrannosaurus rex: Unveiling the True Nature of the King
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Tyrannosaurus rex, commonly known as T.rex, is often the first dinosaur that comes to mind for many. Since its formal identification in 1905, it has captivated audiences worldwide, gaining notoriety unmatched by any other prehistoric creature. However, the way we envision this fascinating predator is often quite different from the reality of the creature that roamed western North America 66 million years ago.
To better understand the 'tyrant lizard king', we must move past the clichés popularized by media and concentrate on scientific findings. Thankfully, T.rex is the most thoroughly researched dinosaur, providing us with a wealth of knowledge.
Our tribute to Tyrannosaurus is divided into two sections for easier understanding:
Part 1 focuses on dispelling prevalent misunderstandings about Tyrannosaurus and offers insights into its general description.
You can find the first part below:
T.rex: Beyond the Pop Culture Monster
The clash between the cinematic monster and a dinosaur from 66 million years ago…
Part 2 delves into additional facets of T.rex’s paleobiology, including its evolutionary background and paleoenvironment.
(Beginning of Part 2)
# Growth
Both Tyrannosaurs in general and T.rex specifically exhibited rapid growth rates. Research indicates that the growth curve for tyrannosaurs resembles an S-shape, suggesting that juvenile individuals underwent significant growth spurts during their adolescent years.
It is estimated that juvenile T.rex remained under 1,800 kg (4,000 lb) until they reached around 14 years of age. At this point, their size began to increase dramatically. During this accelerated growth period, a young T.rex could gain an average of 600 kg (1,300 lb) annually for the next four years. Between the ages of 18 to 20, the growth rate slowed significantly, indicating the onset of sexual maturity. Once they attained adult size, their growth rate diminished considerably.
To learn more about T.rex's unique growth pattern, read the article below:
Supercharged King: How T.rex Grew Faster Than Any Other Giant Theropod
T.rex's growth speed parallels that of modern mammals and birds…
# Behavioral Traits
Although often depicted as solitary creatures, Tyrannosaurus may have exhibited social behavior.
Fossils of more than 26 Albertosaurus individuals were discovered together in Canada, hinting that tyrannosaurs might have lived and hunted in packs. These specimens included both adults and juveniles at various developmental stages. Similar findings from Montana revealed three Daspletosaurus skeletons found together in the same bone bed, which contained remains of a large adult, a small juvenile, and another individual of intermediate size.
Some paleontologists interpret these discoveries as evidence that advanced tyrannosaurs (possibly including T.rex) lived in groups and formed lethal packs. However, others remain unconvinced, suggesting that the social interactions of these theropods were more akin to modern Komodo dragons, where non-cooperative individuals might compete over carcasses, sometimes resorting to cannibalism.
# Origins, Evolution & Feathers
Tyrannosaurs first emerged during the Jurassic Period (200–145 million years ago) and remained relatively small for the majority of their 100 million-year existence. These smaller carnivores were agile, rare, and notably feathered.
Given their feathered origins, it has been suggested that T.rex may have also been covered in feathers. While some type of covering may have existed, recent studies based on skin impressions indicate that Tyrannosaurus was primarily scaly. Any feathering, if present, would likely have been limited to the upper body or the area behind the head.
You may read more about tyrannosaurs below:
Tyrannosaurs: The “Kings” of the Cretaceous
Discover the famous T.rex and its relatives…
Throughout the following Cretaceous Period, tyrannosaurs continued to diversify but remained overshadowed by other theropod groups like the allosauroid carcharodontosaurs and the semi-aquatic spinosaurs. It was only after these formidable predators declined that tyrannosaurs grew in size and became the dominant predators of the Northern Hemisphere.
To learn more about the fearsome allosaurs, read the article below:
When Tyrannosaurs Were Prey
The rise and fall of the giant Allosaurs that ruled the Mesozoic world…
Approximately 10 million years before T.rex emerged, tyrannosaurids like Albertosaurus, Gorgosaurus, and Daspletosaurus reigned as apex predators on the North American continent.
Phylogenetic studies indicate that T.rex is more closely related to Tarbosaurus and Zhuchengtyranus, two tyrannosaurids discovered in Mongolia and China, respectively, rather than its North American relatives.
The 'tyrant lizard king' appears to have migrated from Asia, outcompeting its relatives in North America and becoming the sole tyrannosaurid on the continent during the late Mesozoic Era. With no competitors left, T.rex spread widely, ranging from Canada in the north to at least New Mexico in the south.
# What’s On The Menu?
Living in Late Cretaceous North America was perilous, even for the largest carnivores, as prey was challenging to capture. Massive predators like T.rex coexisted with formidable herbivores such as the impressive Triceratops, equipped with massive horns, and the nearly indistinguishable ceratopsid Torosaurus.
While the iconic battle between T.rex and Triceratops is a popular theme in dinosaur media, it is only weakly supported by scientific evidence—until recently.
A remarkable fossil featuring a juvenile Tyrannosaurus and a full-grown Triceratops locked in what seems to be combat may confirm that violent encounters between these species indeed occurred 66 million years ago.
To explore the intriguing story behind this unique fossil, click the article below:
Spectacular Fossil of ‘Dueling Dinosaurs’ Can Finally Reveal Its Secrets
The astonishing find features a juvenile T.rex and a full-grown Triceratops practically intertwined…
The Late Cretaceous herbivore megafauna also included the armored Ankylosaurus (8m/26ft) and Denversaurus (6m/20ft), as well as the giant hadrosaurid Edmontosaurus (12–15m/40–49ft).
With bony armor and a club on its tail, Ankylosaurus was well-equipped against predators.
In contrast, Edmontosaurus lacked any obvious defenses and found safety in numbers, with herds potentially reaching sizes of 10,000–25,000 individuals, making it challenging for a predator to attack such a vast group.
Various smaller prey species also inhabited the ecosystem alongside T.rex. Fast-moving ornithomimosaurs, dome-headed pachycephalosaurs, feathered caenagnathids, and small ornithopods contributed to the diverse environment of Late Cretaceous North America. Each type of prey posed unique challenges, requiring tyrannosaurs to employ different hunting strategies for success.
When not pursuing other animals, T.rex may have also resorted to cannibalism. Evidence suggests that tyrannosaurs, including T.rex, occasionally engaged in cannibalistic behavior. Researchers theorize that a Tyrannosaurus might attack a member of its own species for territory dominance, food, or both.
To learn more about the evidence supporting cannibalism in tyrannosaurs, read the article below:
Tyrannosaurs Were Blood-Thirsty Cannibals After All
Recent finds from New Mexico confirm that tyrannosaurs engaged in cannibalistic behavior…
# Epilogue
Tyrannosaurus rex was a truly extraordinary creature. Armed with powerful jaws, keen senses, a large brain, and potentially advanced social skills, it stood as the largest and heaviest of its kind, ranking among the most significant carnivores to walk the earth. As the apex predator of its ecosystem, T.rex's reign came to an abrupt end due to the catastrophic event that led to the extinction of all non-avian dinosaurs 66 million years ago.
The skeletal remains of this fierce predator continue to inspire awe in museum visitors worldwide, yet bones alone cannot fully convey the true image of this great predator during its lifetime—an image that contrasts sharply with the one popular culture typically presents.
# References
Parrish J.M., Molnar R.E., Currie P.J., Koppelhus E.B.,(2013), Tyrannosaurid Paleobiology, Indiana University Press
Hone D.,(2016) The Tyrannosaur Chronicles, Bloomsbury Publishing Plc
Paul G.S.,(2010), Dinosaurs A Field Guide, A&C Black Publishers Ltd
Ligon S.,(2013), Unearthing a Pack of Albertosaurus, Link: https://www.ualberta.ca/science/dinosaurs/paleontology/the-people-of-paleo/philip-currie/profile-on-philip-currie
Loewen, Mark A; Irmis, Randall B; Sertich, Joseph J. W; Currie, Philip J; Sampson, Scott D (November 6, 2013). “Tyrant Dinosaur Evolution Tracks the Rise and Fall of Late Cretaceous Oceans”. PLOS ONE. 8 (11): e79420. doi:10.1371/journal.pone.0079420. PMC 3819173. PMID 24223179.