Open Paleo

Struthiomimus

Osborn, 1917 STROOTH-ee-o-MIEM-us

From Greek 'stroutheios' (στρούθειος) meaning 'of the ostrich' and 'mimos' (μῖμος) meaning 'mimic' or 'imitator'; meaning 'ostrich mimic', referring to its long-legged, ostrich-like build.

83.6–72.2 million years ago Campanian, Late Cretaceous
Late Cretaceous stages

Struthiomimus is a genus of ornithomimid dinosaurs from the Late Cretaceous of what is now western North America. They were long-legged, bipedal, ostrich-like dinosaurs with toothless beaks. The type species, Struthiomimus altus, is one of the more common, smaller dinosaurs found in Dinosaur Provincial Park. Their overall abundance, in addition to their toothless beak, suggests that these animals were mainly herbivorous or (more likely) omnivorous, rather than purely carnivorous. Similar to the modern ostriches, emus, and rheas (among other birds), these dinosaurs likely lived as opportunistic omnivores, supplementing a largely plant-based diet with a variety of small mammals, reptiles, amphibians, insects, invertebrates, and anything else they could fit into their mouth, as they foraged.

Diagnosis

  1. Manus isotridactyl with elongate and slightly recurved terminal phalanges
  2. Metacarpals I-II incipiently coalescent; pollex phalanges separate and divergent
  3. Pes anisotetradactyl with metatarsals I, II, IV incipiently coalescent; metatarsal V present and reduced
  4. Digit III relatively elongated in pes
  5. Rod-like elongation of prezygapophyses on caudal vertebrae C12-C30
  6. Skull relatively small and edentulous
  7. Cervical ribs firmly coalesced with sides of cervical centra and arches

Species

Struthiomimus altus (Lambe, 1902)

Type species

First named as Ornithomimus altus

From Latin 'altus' meaning 'lofty' or 'noble', applied by Lawrence Lambe when the species was originally described as Ornithomimus altus in 1901.

Holotype
CMN 930 , Canadian Museum of Nature
Material
Complete right hind limb including foot, phalanges of left foot in place, pubic bone, and ischium.
Horizon
Oldman Formation, Campanian, Late Cretaceous , 83.6–72.2 million years ago
Locality
below Berry Creek, Steveville, Alberta, Canada Lambe (1902) records the hind limb "found in 1901, below Berry creek" in the Belly River series, and Russell (1972) gives "Oldman Formation, probably near Steveville ferry crossing", a name that then still covered the beds now in the Dinosaur Park Formation. Claessens and Loewen (2016), using the modern split, place the type in the Oldman Formation, at 78 to 77 Ma.

Notable specimens

  • AMNH 5339

    American Museum of Natural History Found 1914 by Barnum Brown historic

    Nearly complete skeleton found at the Red Deer River, Alberta, that prompted Osborn to make O. altus the type species of the new genus Struthiomimus. Far more complete than the partial-hindlimb holotype, it grounded the genus and Osborn's pioneering horizontal-posture reconstruction.

    Osborn (1917)

References

  1. Osborn, H. F. (1917). Skeletal adaptations of Ornitholestes, Struthiomimus, Tyrannosaurus. Bulletin of the American Museum of Natural History 35(43): 733-771. osborn1917a
  2. Lambe, L. M. (1902). New genera and species from the Belly River Series (mid-Cretaceous). Geological Survey of Canada Contributions to Canadian Palaeontology 3(2): 25-81. doi:10.5281/zenodo.3233762

    Names the species as Ornithomimus altus, on a partial right hind limb.

    lambe1902a
  3. Jones, B. (2026). The Princeton Encyclopedia of Dinosaurs: Theropods. Princeton University Press.

    Source of the appearance features.

    jones2026c
  4. Claessens, L. P. A. M.; Loewen, M. A. (2016). A redescription of Ornithomimus velox Marsh, 1890 (Dinosauria, Theropoda). Journal of Vertebrate Paleontology 36(1): e1034593. Informa UK Limited. doi:10.1080/02724634.2015.1034593

    Places the Struthiomimus altus type in the Oldman Formation, dated 78 to 77 Ma.

    claessens2016a
  5. Russell, D. A. (1972). Ostrich Dinosaurs from the Late Cretaceous of Western Canada. Canadian Journal of Earth Sciences 9(4): 375-402. Canadian Science Publishing. doi:10.1139/e72-031 russell1972a
  6. McFeeters, B.; Ryan, M. J.; Schröder-Adams, C.; Cullen, T. M. (2016). A new ornithomimid theropod from the Dinosaur Park Formation of Alberta, Canada. Journal of Vertebrate Paleontology 36(6): e1221415. Informa UK Limited. doi:10.1080/02724634.2016.1221415

    Moves ROM 1790, from the lower Dinosaur Park Formation, from Struthiomimus altus to Rativates, and places the holotype CMN 930 in neither formation.

    mcfeeters2016a