Tyrannosaurus rex

Locomoción

• An adult Tyrannosaurus rex could walk fast but could not truly run.

  Nivel de evidencia: Evidencia moderadaFuentes · 3

  To run, an animal needs enough leg muscle and bones strong enough for the impact. Models of a 6-9 tonne adult say T. rex had neither for a real run, so estimated top speeds are those of a brisk walk. Juveniles, being lighter, were probably faster.

  Evidencia a favor / en contra · 1

  Evidencia a favor

  • Modelo biomecánico · T. rex limb muscle models limit running speed

    Models of leg muscle mass needed for fast running (Hutchinson & Garcia 2002) and multibody simulations with bone-stress limits (Sellers et al. 2017) both find that a large adult could not run fast.

Alimentación

• Tyrannosaurus rex had one of the strongest bites of any land animal and could crush and eat bone.

  Nivel de evidencia: Evidencia sólidaFuentes · 4

  Three kinds of evidence agree: bitten bones with deep punctures, droppings full of crushed bone, and computer models of the jaw muscles. Together they show a bite strong enough to shatter bone, unusual among dinosaurs.

  Evidencia a favor / en contra · 3

  Evidencia a favor

  • Icnofósil · Tooth-marked Triceratops and Edmontosaurus bones

    Deep punctures and drag marks attributed to T. rex teeth on a Triceratops pelvis, used to estimate bite force experimentally.

  • Icnofósil · Bone-filled tyrannosaur coprolite (Saskatchewan)

    A large coprolite full of crushed bone fragments of a juvenile dinosaur, attributed to T. rex by size and age.

  • Modelo biomecánico · Bite force simulations for T. rex

    Muscle reconstruction and multibody dynamics giving bite forces in the tens of kilonewtons at the back teeth.

Piel y cobertura

• Adult Tyrannosaurus rex had mostly scaly skin; if it had feathers, they were limited.

  Nivel de evidencia: Evidencia moderadaFuentes · 2

  The only T. rex skin found is scaly, and covers small patches from the neck, hips and tail. Its relative Yutyrannus had long feathers, so feathers on the back of T. rex cannot be ruled out, but a fluffy adult T. rex is not supported.

  Evidencia a favor / en contra · 2

  Evidencia a favor

  • Impresión de piel · Scaly skin patches of a T. rex (HMNS / Wyrex)

    Small patches of scaly skin from the neck, pelvis and tail of a T. rex, with no trace of feathers.

  Evidencia en contra

  • Impresión de plumas · Feathered giant tyrannosauroid Yutyrannus

    Long filamentous feathers preserved on a 9 m Early Cretaceous tyrannosauroid from China, showing large tyrannosauroids could be feathered.

Crecimiento

• Tyrannosaurus rex grew very fast as a teenager and reached adult size at around 20 years old.

  Nivel de evidencia: Evidencia sólidaFuentes · 1

  Bones grow in yearly layers, like tree rings. Counting them in T. rex bones shows a growth spurt in the teens, when an individual could gain hundreds of kilograms a year, then a slowdown near 20. Sue is estimated to have died in her late twenties.

  Evidencia a favor / en contra · 1

  Evidencia a favor

  • Histología · Tyrannosaurid bone histology growth curves

    Growth lines counted in thin sections of long bones and ribs of several T. rex individuals, including Sue, fitted to a growth curve with a steep adolescent phase.

    Espécimen: FMNH PR 2081 “Sue”

Vivió en: Hell Creek

hace 68–66 millones de años · llanura aluvial, sistema fluvial, bosque, llanura costera

Warm, humid coastal lowlands and river floodplains west of the retreating Western Interior Seaway at the very end of the Cretaceous, with forests of conifers and flowering plants. The ecosystem ends at the Cretaceous-Paleogene extinction.