The Tyrannosaurus rex, or T. rex, is one of the most recognized dinosaurs. Its immense size and powerful build have long captivated the public imagination. The sheer scale of its feet sparks curiosity, hinting at the adaptations required to support such a large predator. Understanding the T. rex foot provides insight into how this creature navigated its ancient world.
Measuring the T. Rex Foot
Fossil evidence, including preserved bones and trackways, provides measurements for the T. rex foot. The overall length of a T. rex foot, from heel to the tip of the longest toe, was about 3.3 feet (1 meter). The T. rex, like many dinosaurs, walked on its toes. Reconstructed footprints and fossil casts suggest a broad foot; one notable track measured 34 inches (86 cm) long and about two-thirds as wide. Another large footprint measured approximately 33 inches (83 cm) long by 28 inches (71 cm) wide.
Individual footprints found in rocks, representing the part of the foot that contacted the ground, were around 1.55 feet (46 cm) long. Other trackways show footprints up to 26.3 inches long. These impressions provide direct evidence of the T. rex’s immense foot size. The largest known footprint cast is approximately 3 feet long and 70 cm wide.
The Foot’s Design
The T. rex foot was designed for strength and stability, reflecting the animal’s massive body weight. It featured three main weight-bearing toes that faced forward, each with large, blunt claws. A smaller, non-weight-bearing fourth toe, similar to a dewclaw, was also present. This structure, with three forward-pointing toes, is characteristic of many large theropods.
The bones within the foot, specifically the metatarsals and phalanges, were robust to withstand the forces of locomotion. Tyrannosaurs possessed proportionally longer feet compared to other large carnivorous dinosaurs. A unique feature of the tyrannosaur foot is the “arctometatarsus,” where the large middle metatarsal bone is triangular in cross-section and tapers to a narrow ankle. This specialized arrangement allowed for a strong and compact foot structure.
What the Foot Tells Us
The robust design of the T. rex foot was important for supporting the animal’s weight, estimated between 5,000 and 7,000 kilograms (11,000 to 15,500 pounds). Its foot structure provided stability, which was important for an animal that stood up to 12 feet tall at the hips and could reach lengths of 40 feet. The powerful hind limbs, with their specialized feet, were central to its bipedal locomotion.
Paleontologists infer that the T. rex’s foot morphology, especially the arctometatarsus, enabled relatively fast forward movement and agility for its size. Studies of trackways indicate that T. rex likely walked with an alternating stride, suggesting it was limited to a walking pace rather than high-speed running due to stresses on its legs. Ligament attachments within the foot, discovered through new research, suggest adaptations for both long-distance movement and rapid acceleration, highlighting the specialized nature of the T. rex’s feet.