Tyrannosaurus was not a fast runner

  title={Tyrannosaurus was not a fast runner},
  author={John R. Hutchinson and Mariano Garcia},
The fastest gait and speed of the largest theropod (carnivorous) dinosaurs, such as Tyrannosaurus, is controversial. Some studies contend that Tyrannosaurus was limited to walking, or at best an 11 m s-1 top speed, whereas others argue for at least 20 m s-1 running speeds. We demonstrate a method of gauging running ability by estimating the minimum mass of extensor (supportive) muscle needed for fast running. The model's predictions are validated for living alligators and chickens. Applying the… 
Investigating the running abilities of Tyrannosaurus rex using stress-constrained multibody dynamic analysis
A new approach is presented that combines two separate biomechanical techniques (multibody dynamic analysis and skeletal stress analysis) to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex.
The fast and the frugal: Divergent locomotory strategies drive limb lengthening in theropod dinosaurs
Once the limiting effects of body size increase is incorporated, no commonly used metric including the newly suggested distal limb index shows a significant correlation to top speed, suggesting two distinct strategies for promoting limb elongation based on the organisms’ size.
Twenty trackways of Kayentapus minor were exposed on a single bedding plane at the Culpeper Crushed Stone Quarry (Stevensburg, Virginia) in the early 1990’s. These trackways included over 1800
A Computational Analysis of Limb and Body Dimensions in Tyrannosaurus rex with Implications for Locomotion, Ontogeny, and Growth
It is concluded that adult T. rex had body masses around 6000–8000 kg, with the largest known specimen (“Sue”) perhaps ∼9500 kg, and that the limb “antigravity” muscles may have been as large as or even larger than those of ratite birds, which themselves have the most muscular limbs of any living animal.
Estimating dinosaur maximum running speeds using evolutionary robotics
  • W. Sellers, P. Manning
  • Environmental Science
    Proceedings of the Royal Society B: Biological Sciences
  • 2007
Simple musculoskeletal models of three extant and five extinct bipedal species are presented and it is concluded that the values presented for the five extinct species are reasonable predictions given the modelling assumptions made.
Constraint-Based Exclusion of Limb Poses for Reconstructing Theropod Dinosaur Locomotion
This analysis shows that skeletal information alone has limited value for discerning mid-stance poses, and indicates that unpreserved parameters such as masses, forces, and moments are required to study a fossil as a functioning animal, rather than as a moving set of bones.
March of the Titans: The Locomotor Capabilities of Sauropod Dinosaurs
This model represents the best current simulation of the gait of these giant animals, and it is likely that there are as yet unknown mechanical mechanisms, possibly based on passive elastic structures that should be incorporated to increase the efficiency of the animal's locomotion.
An Older and Exceptionally Large Adult Specimen of Tyrannosaurus rex
An extremely large and relatively complete (roughly 65%) skeleton of Tyrannosaurus rex (RSM P2523.8) is described, offering support for prior hypotheses that a sampling bias occurs throughout the Dinosauria, making it likely that most taxa grew to significantly greater size than current known specimens indicate.
Using step width to compare locomotor biomechanics between extinct, non-avian theropod dinosaurs and modern obligate bipeds
Step width—the mediolateral distance between successive footfalls—was investigated with respect to speed (stride length) in non-avian theropod trackways of Late Triassic age, inferring a continuous locomotor repertoire, possibly including grounded running.
Craniocervical feeding dynamics of Tyrannosaurus rex
The results indicate that adult T. rex could strike rapidly at prey and engage in complexly modulated inertial feeding, as seen in extant archosaurs.


It is concluded that ornithomimid and Tyrannosaurid legs functioned in a similar manner, and always exhibit the features normally associated with a fast running gait, in contrast to modern animals, in which elephants as gigantic as large tyrannosaurids have limbs that are modified for a slow walking gait.
Body mass, bone “strength indicator,” and cursorial potential of Tyrannosaurus rex
The implication is that the cursorial potential of Tyrannosaurus was limited, a conclusion consistent with observed declines in sprint speed with increasing body mass in living animals, and also consistent with the tibia/femur length ratio, and the construction of the hip joint, of the dinosaur.
Pelvic and hindlimb musculature of Tyrannosaurus rex (Dinosauria: Theropoda)
A new reconstruction of the pelvic and hindlimb muscles of the large theropod dinosaur Tyrannosaurus rex is developed, using data from both extant and fossil turtles, lepidosaurs, and archosaurs to constrain inferences concerning the soft‐tissue structures in T. rex.
Mechanics of posture and gait of some large dinosaurs
The positions of dinosaurs' centres of mass, derived from models, show that some large quadrupedal dinosaurs supported most of their weight on their hind legs and were probably capable of rearing up on their hinder legs.
Energetics of bipedal running. II. Limb design and running mechanics.
The greater volume of muscle recruited by bipedal runners appears to offset the economy of slower rates of force generation, supporting the hypothesis and providing a simple explanation for why it costs the same to run on two and four legs.
Sauropod habits and habitats
  • W. Coombs
  • Environmental Science, Geography
  • 1975
Guineafowl hind limb function. I: Cineradiographic analysis and speed effects
Avian striding bipedalism was studied in the helmeted guineafowl, Numida meleagris with direct visualization of the skeleton in X‐ray images allowed changes in pelvic and femoral position to be quantified with great accuracy for the first time.
Mechanical work in terrestrial locomotion: two basic mechanisms for minimizing energy expenditure.
During running, trotting, hopping, and galloping, the power per unit weight required to maintain the forward speed of the center of mass is almost the same in all the species studied and the sum of these two powers is almost a linear function of speed.
Allometry of the leg muscles of mammals
Differences between primates; fissipedes, bovids and bipedal hoppers are demonstrated and departures from geometric similarity in mammals in general are noted and discussed.
Allometry of the leg muscles of birds
The linear dimensions of bones, tendon cross-sectional areas, and muscle masses and fibre areas in the legs of the non-running birds scaled closely according to the requirements for geometric similarity, but the confidence limits are often wide.