Struthiomimus

Struthiomimus was an agile, ostrich-mimic theropod that inhabited the subtropical river floodplains of Alberta during the Late Cretaceous epoch. Reaching over four metres in length, it was remarkably similar in overall silhouette to a modern ostrich, albeit with a long, stiff bony tail to counterbalance its body while running. Its limbs were notably gracile, built for sustaining high speeds across open ground to evade formidable predators such as Gorgosaurus. Unlike some close relatives, its forelimbs were comparatively long and equipped with three slender fingers bearing curved claws. Its skull was light and toothless, terminating in a keratinous beak designed to crop vegetation or snatch small prey. While early reconstructions envisioned it as an exclusively egg-eating scavenger, modern palaeontologists view Struthiomimus as an adaptable omnivore that consumed a diverse menu of seeds, leafy greens, small invertebrates, and lizards.

Its hands bore three fingers with distinctively curved claws, possibly used to pull down tree branches.

Where and when

Struthiomimus lived in the Late Cretaceous, from 76.5 to 74.8 million years ago (Campanian age). Its remains come from Canada, in the Dinosaur Park Formation.

The numbers

Length 4.2 m (estimates run from 4 to 4.3 m). Mass about 170 kg. Hip height about 1.4 m. That is 2.5 human-lengths, or 0.38 of a double-decker bus. These are estimates from near-complete skeleton; fields marked estimated by the site are length, mass, hip height.

Compare Struthiomimus with a bus Place on the timeline