The Tyrannosaurus rex, also known as the T-Rex, is undoubtedly one of the most iconic dinosaurs of all time. Towering over other predators and prey alike, the T-Rex struck fear into anything that crossed its path during the late Cretaceous period. However, despite its massive size and bone-crushing bite force, the T-Rex was not invincible. So what massive beast could have taken down this mighty king of dinosaurs?
Triceratops
One of the top contenders for killing a T-Rex is the Triceratops. This three-horned herbivore was equipped with long horns and a bony frill around its head, making it a formidable opponent. Triceratops fossils have been found bearing T-Rex tooth marks, indicating they occasionally battled each other. While an adult Triceratops would have weighed only around 13,000 lbs compared to the T-Rex at over 15,500 lbs, it could have used its horns and beak to injure or kill a T-Rex during an intense fight.
Evidence of Triceratops vs T-Rex battles
In 2010, paleontologists found a Triceratops pelvis with a T-Rex tooth embedded in it, likely broken off during a fight where the Triceratops survived. Even more dramatic evidence comes from a Triceratops skull discovered in 2021 with two large puncture holes matching T-Rex bite marks. The punctures had started to heal, meaning the Triceratops survived the encounter. These discoveries prove Triceratops and T-Rexes occasionally battled each other and dealt damaging injuries. With its imposing horns and fighting spirit, an adult Triceratops certainly could have killed a T-Rex under the right circumstances.
Ankylosaurus
Another top contender for T-Rex killer is the tank-like Ankylosaurus. Covered in thick, bony armor plates all down its back and flanks, with more armor on its eyelids and a heavy club on the end of its tail, an Ankylosaurus was built like a walking fortress. Weighing around 13,000 lbs as an adult, it was close in size to the T-Rex. While not built for speed, its defenses would have allowed it to outlast a T-Rex in battle and eventually wear it down.
Ankylosaurus killing methods
With its heavily armored body, an Ankylosaurus likely withstood T-Rex bites to the flanks during combat. If a T-Rex tried to flip it over to access its more vulnerable belly, the Ankylosaurus could strike back powerfully with its clubbed tail. Skeletal evidence shows Ankylosaurus tails breaking T-Rex leg bones. A club strike to the leg could cripple a T-Rex’s movement or knock it over, allowing the Ankylosaurus to rain more blows down on it. A solid club hit to the head could have shattered a T-Rex’s skull and brain, decisively winning the fight for the Ankylosaurus.
Spinosaurus
The Spinosaurus is also a potential T-Rex killer. Larger than the T-Rex at around 50 feet long and over 7 tons, it had immense jaws filled with conical teeth ideal for catching fish. With its crocodile-like skull and dense bones, it was likely an aggressive and powerful predator. Its most distinctive feature was the 6-foot tall neural spines growing from its vertebrae to form a “sail” along its back. While the purpose of this sail is still debated, it could have helped with display or thermoregulation.
Spinosaurus vs T-Rex
With its larger size and tooth-filled jaws, a Spinosaurus likely had the advantage in head-to-head combat with a T-Rex. It may have used its agility in water to ambush hunting T-Rexes. A Spinosaurus could grab a T-Rex with its jaws, using its powerful neck to twist and shake the T-Rex violently or slam it to the ground. It may have also used its clawed forelimbs to slash at a T-Rex while grappling with its jaws. With enough crushing bites and lacerations, a Spinosaurus could mortally wound even the mighty T-Rex.
Giganotosaurus
Last but certainly not least on the list of T-Rex killers is Giganotosaurus. Hailing from South America, it was one of the largest terrestrial carnivores ever at around 45 feet long and 8 tons. Its skull was over 5 feet long, filled with 8-inch serrated teeth. While its bite force was weaker than a T-Rex, these knife-like teeth could inflict grievous slicing wounds. With its longer legs, Giganotosaurus was also faster than the stockier T-Rex.
Giganotosaurus hunting tactics
With its speed and agility, a Giganotosaurus likely avoided direct combat with T-Rexes when possible, instead using hit and run tactics. It could use its jaws like hatchets, tearing huge gashes in a T-Rex with slashing bites from its head and neck’s greater range of motion. Then it would dance out of the way of any answering bites from the wounded T-Rex. Enough blood loss and trauma from these biting attacks could weaken the T-Rex until the Giganotosaurus moved in for the kill. Some paleontologists even think the Giganotosaurus hunted in packs, which would have made them even more dangerous to lone T-Rexes.
Other possible T-Rex killers
While the dinosaurs described above are the most likely killers of T-Rex based on size, fossils, and hypothesized behavior, a few other contenders exist:
- Allosaurus – Smaller carnivore that may have hunted in packs
- Saurophaganax – Large carnivore similar to Allosaurus
- Torvosaurus – Larger carnivore reaching 33 feet long
These theropods all lived alongside T-Rex in North America during the late Cretaceous. Working together in groups, they could possibly have brought down injured, sick, or juvenile T-Rexes. But evidence for pack hunting behavior in these species is inconclusive.
Tyrannosaurus rex killers – The fossil evidence
Direct fossil evidence of one dinosaur killing a T-Rex is relatively rare. However, some compelling examples exist that shed light on the issue of what dinosaurs were capable of killing the once mighty T-Rex:
| Fossil | Description |
|---|---|
| Triceratops pelvis with T-Rex tooth embedded | Shows a Triceratops survived a T-Rex attack and broke off one of its teeth |
| Triceratops skull with healed T-Rex bites | Additional evidence of a Triceratops living through a T-Rex attack |
| Broken T-Rex leg bones | Bones shattered by blows from an Ankylosaurus tail club |
| T-Rex dentary bone with tooth marks from another Tyrannosaur | Possible evidence of infighting between T-Rexes |
These fossils provide tantalizing clues that Triceratops, Ankylosaurus, and possibly even other T-Rexes could hold their own against the apex predator T-Rex. More fossils may be found that reveal additional details about these epic dinosaur battles.
Conclusion
In summary, the two dinosaurs most likely to have killed a T-Rex based on size, natural weapons, and fossil evidence are Triceratops and Ankylosaurus. The horns and beak of an adult Triceratops could inflict mortal injuries if it managed to strike the vulnerable areas of a T-Rex. Likewise, the bony body armor and massive tail club of an Ankylosaurus gave it defense and offense capable of taking down a T-Rex after an extended duel.
Spinosaurs like Giganotosaurus also potentially could best T-Rex thanks to their large size, deadly teeth, and high speed. Under the right circumstances, other large theropods like Allosaurus may have also been able to kill a T-Rex, especially if working in groups. But Triceratops and Ankylosaurus were undoubtedly the most formidable T-Rex-fighting dinosaurs pound-for-pound based on their natural weapons, defensive equipment, and the fossil evidence of conflict between them.
While it was clearly an apex predator of its environment, the Tyrannosaurus rex was not invulnerable. When this tyrant lizard king picked the wrong fight, it could ultimately fall victim to the horns, club, teeth, or teamwork of another formidable Cretaceous dinosaur.