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Feathered, long-legged Oviraptor with a short toothless beak walking to the left
Life restoration of Oviraptor philoceratops from the Djadokhta Formation of Mongolia, shown fully feathered.Image credit: PaleoNeolitic, CC BY 4.0, via Wikimedia CommonsCC BY 4.0Source (opens in a new tab)

Oviraptor philoceratops

Pronounced OH-vih-RAP-tor fil-oh-SERR-ah-tops

Maniraptora · Oviraptoridae

The "egg thief", a beaked, feathered theropod from the Late Cretaceous of Mongolia, found in 1923 lying on a nest of eggs. Later finds showed the nest was its own: it was brooding, not stealing.

  • Bipedal
  • Feathered
  • Eggs known
  • Famous specimen
Compare
Period
Cretaceous· Campanian
Diet
Omnivore
Length
1.6–2 m
Mass
33–40 kg
Location
Ömnögovi Province, Mongolia, Asia

Quick answers

How big was Oviraptor philoceratops?
Oviraptor philoceratops was about 1.6–2 m long. It stood about 0.7–0.9 m tall at the hips. It weighed about 33–40 kg. (Wikipedia: Oviraptor 2026; Paul 2016)
When did Oviraptor philoceratops live?
Oviraptor philoceratops lived during the Late Cretaceous, about 75–71 million years ago. (Paleobiology Database: Oviraptor philoceratop… 2026; Dashzeveg et al. 2005)
Where have Oviraptor philoceratops fossils been found?
Fossils of Oviraptor philoceratops have been found in Djadokhta Formation (Ömnögovi Province) and Mongolia. (Osborn 1924; Norell et al. 1994)
What did Oviraptor philoceratops eat?
Oviraptor philoceratops was a omnivore. (Osborn 1924; Norell et al. 1994)
Who named Oviraptor philoceratops, and when?
Oviraptor philoceratops was described by Henry Fairfield Osborn in 1924. (Osborn 1924; Paleobiology Database: Oviraptor philoceratop… 2026)

On this page

Period
Cretaceous75–71 Ma
Diet
Omnivore
Length
1.6–2 m
Mass
0–0 t
Location
Mongolia, Asia
Classification
Maniraptora · Oviraptoridae
Described
1924, Henry Fairfield Osborn

Overview

Oviraptor philoceratops lived among the dunes of the Djadokhta Formation of Mongolia in the Late Cretaceous. The American Museum's Central Asiatic Expedition found its only skeleton at the Flaming Cliffs in 1923, lying over a nest of about fifteen eggs, and Henry Fairfield Osborn named it in 1924.

Osborn thought the eggs belonged to Protoceratops and named it "egg thief, fond of ceratopsians", while warning that the name might be misleading. In 1994 an oviraptorid embryo was found inside the same type of egg, and in 1995 a related oviraptorid was found sitting on its nest like a brooding bird (Norell et al. 1994, 1995). The type Oviraptor was most likely a parent that died brooding its own eggs.

It was a small, toothless theropod, about 1.6 to 2 m long, with a deep beak, long arms with three clawed fingers and, like its relatives, feathers. The holotype skull is badly crushed, but related oviraptorids suggest a crest.

Name meaning

"Egg seizer" or "egg thief", from Latin ovum and raptor; philoceratops, "fond of ceratopsians", for the eggs once thought to be Protoceratops's (Osborn 1924).

Biology & evidence

What scientists think about how this animal lived, and how strong the evidence for each idea is.

Nesting

  • The Oviraptor holotype died brooding its own nest.

    Evidence level: Strong evidence

    An oviraptorid embryo in the same type of egg and relatives found sitting on nests show the eggs were its own.

    Evidence for / against · 2
    Evidence for

    • Specimen · Oviraptorid embryo in a Flaming Cliffs-type egg

      An oviraptorid embryo inside an egg of the type found under the Oviraptor holotype in 1923.

    • Specimen · Oviraptorid preserved brooding its nest

      An oviraptorid skeleton sitting on its nest in a bird-like brooding posture.

Nest of elongate eggs (AMNH FR 6508) at the American Museum of Natural History, of the kind first attributed to Protoceratops and later shown to be oviraptorid.Image credit: Steve Starer from Commack NY, USA, CC BY 2.0, via Wikimedia Commons, American Museum of Natural HistoryCC BY 2.0Source (opens in a new tab)

Size

Length
1.6–2 m

(6.6 ft)

Based on AMNH 6517

Height
0.8 mpublished range 0.7–0.9 m

(2.6 ft)

Mass
33–40 kg

Based on AMNH 6517

Oviraptor philoceratops was about 2 m (6.6 ft) long, roughly 1.1 times the height of a 1.8 m adult human.

Timeline

Lived from about 75 to 71 million years ago (Ma), within the Mesozoic era (252–66 Ma).

Periods: Campanian (83.6–72.1 Ma), Late Cretaceous (100.5–66 Ma)

Djadokhta Formation, about 75-71 Ma: magnetostratigraphy suggests, without clearly establishing, deposition during the late Campanian polarity changes (Dashzeveg et al. 2005). PBDB bins the type collection in the late Campanian (83.6-72.2 Ma).

Location

Formations

Map data: Natural Earth (public domain). Modern positions, not where the continents were then.

These are the places where fossils have been found, not the full area where the animal lived.

Ecosystem

Lived in: Djadokhta

75–71 million years ago · desert / dunes, other

An arid landscape of sand dunes and interdune areas in the Late Cretaceous Gobi, with occasional water. Sandslides and dune collapses buried animals alive, preserving articulated skeletons and nests.

Same ecosystem

Velociraptor mongoliensis

Cretaceous· CampanianCarnivore

Same ecosystem

Protoceratops andrewsi

Cretaceous· CampanianHerbivore

Classification

  1. cladeDinosauria
  2. cladeSaurischia
  3. cladeTheropoda
  4. cladeCoelurosauria
  5. cladeManiraptora
  6. infraorderOviraptorosauria
  7. familyOviraptoridae
  8. genusOviraptor
  9. speciesOviraptor philoceratops

Taxonomic status: Valid

Fossil record

The Oviraptor philoceratops holotype AMNH 6517 as figured in Edwin H. Colbert's The Dinosaur Book (1951).Image credit: Internet Archive Book Images (from Colbert, The Dinosaur Book, 1951), Public domain, via Wikimedia Commons, American Museum of Natural HistoryPublic domainSource (opens in a new tab)
Specimens
Catalog numberStatusInstitutionFound
AMNH 6517HolotypeAmerican Museum of Natural History (AMNH)1923

What has been found

Holotype: AMNH 6517

  • Preserved
  • Partial
  • Reconstructed
  • Unknown / not recorded
Region by region (table)
Skeleton regions of Holotype: AMNH 6517
RegionState
SkullPartial · Badly crushed.
MandibleUnknown / not recorded
TeethUnknown / not recorded
Cervical vertebraePartial
Dorsal vertebraePartial
SacrumUnknown / not recorded
Caudal vertebraeUnknown / not recorded
RibsPartial
GastraliaUnknown / not recorded
Scapula / shoulder girdlePreserved · With the furcula.
HumerusUnknown / not recorded
Forearm (radius / ulna)Preserved
Hand (manus)Partial
PelvisPartial · Left ilium.
FemurUnknown / not recorded
Tibia / fibulaUnknown / not recorded
Foot (pes)Unknown / not recorded
Skeletal reconstruction of Oviraptor philoceratops, with missing parts based on Citipati osmolskae.Image credit: Iofry, CC BY-SA 4.0, via Wikimedia Commons (unmodified except resizing)CC BY-SA 4.0 (unmodified)Source (opens in a new tab)

All specimens

Discovery

Year described
1924
Described by
Henry Fairfield Osborn
Type specimen
AMNH 6517
American Museum of Natural History display asking which dinosaur laid the Flaming Cliffs eggs, the question behind the name Oviraptor ('egg thief').Image credit: Ryan Somma, CC BY-SA 2.0, via Wikimedia Commons (unmodified except resizing), American Museum of Natural HistoryCC BY-SA 2.0 (unmodified)Source (opens in a new tab)

Discovery timeline

  1. 1923 · First material found

    Oviraptor found on a nest at the Flaming Cliffs

    The Central Asiatic Expedition finds a skeleton lying over a nest of eggs.

    People: Roy Chapman Andrews

  2. 1924 · Formally described

    Osborn names Oviraptor philoceratops

    Named with Velociraptor and Saurornithoides; the "egg thief".

    People: Henry Fairfield Osborn

  3. 1994 · Revision

    Oviraptorid embryo identifies the Flaming Cliffs eggs

    Norell and colleagues show the eggs are oviraptorid, not Protoceratops.

    People: Mark A. Norell, James M. Clark

Sources

  1. (2026). Paleobiology Database: Oviraptor philoceratops occurrence 1244254 (collection 46152). The Paleobiology Database (paleobiodb.org), data service 1.2, accessed 2026-09-23. https://paleobiodb.org/data1.2/colls/list.json?coll_id=46152&show=paleoloc,strat,loc,ref,geo&pgm=gplates&vocab=pbdb (opens in a new tab)
  2. (2026). Wikipedia: Oviraptor. Wikipedia (English), accessed 2026-09-24. https://en.wikipedia.org/wiki/Oviraptor (opens in a new tab)
  3. Dashzeveg, D., Dingus, L., Loope, D. B., Swisher, C. C., III, Dulam, T. & Sweeney, M. R. (2005). New stratigraphic subdivision, depositional environment, and age estimate for the Upper Cretaceous Djadokhta Formation, southern Ulan Nur Basin, Mongolia. American Museum Novitates 3498: 1-31. https://digitallibrary.amnh.org/server/api/core/bitstreams/0df4baac-12e4-44ae-8ef7-3328b22e8604/content (opens in a new tab)
  4. Norell, M. A., Clark, J. M., Chiappe, L. M. & Dashzeveg, D. (1995). A nesting dinosaur. Nature 378: 774-776. doi:10.1038/378774a0 (opens in a new tab)
  5. Norell, M. A., Clark, J. M., Dashzeveg, D., Barsbold, R., Chiappe, L. M., Davidson, A. R., McKenna, M. C., Perle, A. & Novacek, M. J. (1994). A theropod dinosaur embryo and the affinities of the Flaming Cliffs dinosaur eggs. Science 266: 779-782. doi:10.1126/science.266.5186.779 (opens in a new tab)
  6. Osborn, H. F. (1924). Three new Theropoda, Protoceratops zone, central Mongolia. American Museum Novitates 144: 1-12.
  7. Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd edition). Princeton University Press.