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CretaceousomnivoreFossil completeness: excellent

Ornithomimus edmontonicus

Pronunciation: or-NITH-oh-MY-mus ed-mon-TON-ih-kus

A long-legged Canadian ornithomimid known from complete skeletons and fossils preserving a shaggy coat and adult wing-like arm feathers.

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Ornithomimus edmontonicus

The page URL and title are included automatically. Optional contact details are used only to discuss this report. Do not submit private information or precise sensitive fossil-site coordinates.

Last updated 26 July 2026

Feathered side-view reconstruction of OrnithomimusArt by TotalDino · CC BY-SA 4.0

Field guide

Overview

Ornithomimus edmontonicus was an ostrich-like theropod from the latest Cretaceous of Alberta. Its small toothless head, long neck, slender limbs and three-toed feet formed a lightweight body suited to rapid terrestrial movement. Fossils described in 2012 preserve filamentous body feathers in young and adult animals, while mature individuals carried longer, wing-like feathers on the forearms. These flightless structures may have served display or brooding.

Its fossils occur between approximately 72.5 and 66 million years ago. Values shown here are approximate and reflect the current curated seed dataset.

Form and function

Anatomy

The narrow skull ended in a toothless keratinous beak. Large eyes, a flexible neck, long arms with three slender fingers and extremely elongated hind limbs gave it an avian silhouette. Hollow bones reduced weight. Filamentous feathers covered much of the body, and adults developed pennibrachia—wing-like forearms that could not power flight.

  • Small toothless skull with a keratinous beak
  • Long neck and lightweight hollow skeleton
  • Very long hind limbs with three weight-bearing toes
  • Filamentous feather covering across the body
  • Wing-like forearm feathers in mature individuals
  • Long hands with three slender fingers

Evolutionary position

Scientific classification

  1. 1Dinosauriaclade
  2. 2Saurischiaclade
  3. 3Theropodaclade
  4. 4Tetanuraeclade
  5. 5Coelurosauriaclade
  6. 6Ornithomimosauriaclade
  7. 7Ornithomimidaefamily
  8. 8Ornithomimusgenus
  9. 9Ornithomimus edmontonicusspecies

This simplified classification path shows one placement from Dinosauria to this species. Each step is clickable, and other analyses may support alternative relationships.

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Scale

Size comparison

Scientific record

Discovery and naming

Charles M. Sternberg collected a nearly complete skeleton, CMN 8632, from the Horseshoe Canyon Formation in Alberta in 1914 and named Ornithomimus edmontonicus in 1933. Several specimens were later separated as Dromiceiomimus, but many researchers now regard that genus as indistinguishable from Ornithomimus. Alberta discoveries reported in 2012 provided the first feather evidence for ornithomimosaurs.

Discovery credit: Charles M. Sternberg.

Naming authors: Charles M. Sternberg.

Palaeoenvironment

Habitat and behaviour

Ornithomimus occupied coastal floodplains, river channels and wooded environments in Late Cretaceous Alberta. It shared these landscapes with hadrosaurs, ceratopsians, ankylosaurs and tyrannosaurids.

Its long legs indicate efficient running, although a precise top speed cannot be calculated. The toothless beak and generalized body plan are compatible with omnivory, but direct dietary evidence is limited. Adult-only arm fans may have been used for display, brooding or balance.

Worth knowing

Field notes

  • Young and adult specimens preserve different feather arrangements.
  • Adults developed wing-like arm feathers even though the animal could not fly.
  • Its name means bird mimic.
  • Some fossils once called Dromiceiomimus may belong to this species.

Fossil distribution

Fossil locations

Drumheller–Horseshoe Canyon fossil regionDrumheller–Horseshoe Canyon fossil region, Alberta, Canada
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Drumheller–Horseshoe Canyon fossil region

Alberta, Canada

Horseshoe Canyon Formation

regional marker

Markers are deliberately approximate. They identify published fossil areas without exposing sensitive excavation coordinates.

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Fossil specimen record

Museums and research collections

Canadian Museum of Nature

verified

Ottawa, Canada

The museum houses holotype CMN 8632, a nearly complete skeleton collected by Charles M. Sternberg.

Record type: originalChecked 26 July 2026Institution website

A research repository is not necessarily a public exhibit. Loan and display status can change, so check with the institution before visiting.

Scientific uncertainty

  • Whether Dromiceiomimus is distinct from Ornithomimus remains debated.
  • The beak does not reveal a precise diet; omnivory is a broad interpretation.
  • The function of the adult arm feathers is inferred rather than observed.
  • No reliable numerical maximum running speed can be recovered from the skeleton alone.

Evidence

References and sources

  1. 01
    The Paleobiology Database

    Open source
  2. 02
    Feathered non-avian dinosaurs from North America provide insight into wing origins

    Darla K. Zelenitsky, François Therrien, Gregory M. Erickson and 4 coauthors · Science 338(6106), 510–514 · 2012

    Open source
  3. 03
    Ornithomimus edmontonicus collection record

    Canadian Museum of Nature

    Open source