DinoDex
Slender, long-tailed Coelophysis walking on two legs, shown in side view with a scale bar
Life reconstruction of Coelophysis bauri with a 50 cm scale bar, by Jeff Martz for Petrified Forest National Park.Image credit: Jeff Martz (National Park Service), Public domain, via Wikimedia Commons, Petrified Forest National ParkPublic domainSource (opens in a new tab)

Coelophysis bauri

Pronounced SEE-loh-FY-sis BOW-er-eye

Neotheropoda · Coelophysidae

One of the earliest known theropods, a slender, 3 m predator from the Late Triassic of New Mexico. Hundreds of skeletons from the Ghost Ranch quarry make it one of the best-known early dinosaurs.

  • Bipedal
  • Famous specimen
Compare
Period
Triassic· Late Triassic
Diet
Carnivore
Length
3 m
Mass
15–25 kg
Location
New Mexico, United States

Quick answers

How big was Coelophysis bauri?
Coelophysis bauri was about 3 m long. It stood about 0.5–0.7 m tall at the hips. It weighed about 15–25 kg. (Wikipedia: Coelophysis 2026; Paul 2016)
When did Coelophysis bauri live?
Coelophysis bauri lived during the Late Triassic, about 205.7–201.4 million years ago. (Paleobiology Database: Coelophysis bauri coll… 2026)
Where have Coelophysis bauri fossils been found?
Fossils of Coelophysis bauri have been found in Chinle Formation (New Mexico) and United States. (Cope 1887; Colbert 1947)
What did Coelophysis bauri eat?
Coelophysis bauri was a carnivore. (Cope 1887; Colbert 1947)
Who named Coelophysis bauri, and when?
Coelophysis bauri was described by Edward Drinker Cope in 1887. (Cope 1887; Paleobiology Database: Coelophysis bauri coll… 2026)

On this page

SEE-loh-FY-sis BOW-er-eye

Period
Triassic205.7–201.4 Ma
Diet
Carnivore
Length
3 m
Mass
0–0 t
Location
United States
Classification
Neotheropoda · Coelophysidae
Described
1887, Edward Drinker Cope

Overview

Coelophysis bauri lived at the end of the Triassic in what is now northern New Mexico, near the equator of the supercontinent Pangaea. Edward Drinker Cope named its first, fragmentary bones as Coelurus bauri in 1887 and moved them to the new genus Coelophysis in 1889.

In 1947 George Whitaker, in Edwin Colbert's American Museum crew, found a bonebed at Ghost Ranch packed with complete skeletons of all sizes. Because Cope's scrappy type bones could not be matched to them with certainty, the ICZN made a complete Ghost Ranch skeleton, AMNH 7224, the neotype in 1996.

It was a lightly built, two-legged hunter up to about 3 m long with a long, narrow head and grasping hands. Some Ghost Ranch skeletons were long said to hold eaten juveniles of their own kind, but Nesbitt and colleagues (2006) showed the "gut contents" were small crocodile-line reptiles, not young Coelophysis.

Name meaning

"Hollow form", from Greek koilos ("hollow") and physis ("form"), for its hollow bones; bauri honours the palaeontologist Georg Baur (Cope 1887, 1889).

Biology & evidence

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

Feeding

  • Coelophysis ate small crocodile-line reptiles.

    Evidence level: Strong evidence

    The gut contents of Ghost Ranch skeletons belong to early crocodylomorphs.

    Evidence for / against · 1
    Evidence for

    • Specimen · Coelophysis "cannibal" gut contents re-examined

      Anatomy and histology of the supposed juvenile Coelophysis inside two Ghost Ranch skeletons show they are early crocodylomorphs.

Coelophysis bauri skeleton with crocodylomorph bones in its gut region, once read as evidence of cannibalism, at the American Museum of Natural History.Image credit: Smokeybjb, CC BY-SA 3.0, via Wikimedia Commons (unmodified except resizing), American Museum of Natural HistoryCC BY-SA 3.0 (unmodified)Source (opens in a new tab)

Size

Length
3 m

(9.8 ft)

Height
0.6 mpublished range 0.5–0.7 m

(2 ft)

Based on Ghost Ranch adults

Mass
15–25 kg
Coelophysis bauri was about 3 m (9.8 ft) long, roughly 1.7 times the height of a 1.8 m adult human.

Timeline

Lived from about 205.7 to 201.4 million years ago (Ma), within the Mesozoic era (252–66 Ma).

Periods: Late Triassic (237–201.4 Ma), Triassic (251.9–201.4 Ma)

Rhaetian bin of the Ghost Ranch neotype quarry in PBDB. Cope's original sites are binned as Norian (227.3-205.7 Ma); the Petrified Forest Member is dated to about 211.9 Ma (secondary), and the age of the Ghost Ranch beds is debated.

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

Late Triassic scene with Postosuchus, Coelophysis and the dicynodont Placerias, animals of the Chinle Formation.Image credit: ABelov2014, CC BY-SA 3.0, via Wikimedia Commons (unmodified except resizing)CC BY-SA 3.0 (unmodified)Source (opens in a new tab)

Lived in: Chinle (Ghost Ranch)

205.7–201.4 million years ago · floodplain, river system

Late Triassic river floodplains of north-central New Mexico, near the equator of Pangaea; the Ghost Ranch bonebed is a crevasse-splay deposit.

Classification

  1. cladeDinosauria
  2. cladeSaurischia
  3. cladeTheropoda
  4. cladeNeotheropoda
  5. superfamilyCoelophysoidea
  6. familyCoelophysidae
  7. genusCoelophysis
  8. speciesCoelophysis bauri

Taxonomic status: Valid

Fossil record

Cast of Coelophysis bauri skeletons from the Ghost Ranch quarry, New Mexico, exchanged with the American Museum of Natural History and exhibited at the Natural History Museum, London.Image credit: Daderot, CC0, via Wikimedia Commons, Natural History Museum, LondonCC0 1.0Source (opens in a new tab)
Specimens
Catalog numberStatusInstitutionFound
AMNH 7224NeotypeAmerican Museum of Natural History (AMNH)1947

What has been found

Neotype: AMNH 7224

  • Preserved
  • Partial
  • Reconstructed
  • Unknown / not recorded
Region by region (table)
Skeleton regions of Neotype: AMNH 7224
RegionState
SkullPreserved
MandibleUnknown / not recorded
TeethUnknown / not recorded
Cervical vertebraePreserved
Dorsal vertebraePreserved
SacrumUnknown / not recorded
Caudal vertebraeUnknown / not recorded
RibsUnknown / not recorded
GastraliaUnknown / not recorded
Scapula / shoulder girdleUnknown / not recorded
HumerusUnknown / not recorded
Forearm (radius / ulna)Unknown / not recorded
Hand (manus)Unknown / not recorded
PelvisPreserved
FemurPreserved
Tibia / fibulaUnknown / not recorded
Foot (pes)Unknown / not recorded
Close-up of the skull of the Coelophysis bauri neotype AMNH 7224 at the American Museum of Natural History.Image credit: Skye McDavid, CC BY 4.0, via Wikimedia Commons, American Museum of Natural HistoryCC BY 4.0Source (opens in a new tab)

All specimens

Discovery

Year described
1887
Described by
Edward Drinker Cope
Type specimen
AMNH 7224

Discovery timeline

  1. 1881 · First material found

    Baldwin collects the first Coelophysis bones

    David Baldwin collects fragmentary bones at Arroyo Seco, Rio Arriba County, for Cope.

    People: David Baldwin

  2. 1887 · Formally described

    Cope names Coelurus bauri

    Cope names the species in the genus Coelurus; he erects Coelophysis for it in 1889.

    People: Edward Drinker Cope

  3. 1947 · Specimen recovered

    Ghost Ranch Coelophysis quarry discovered

    George Whitaker of Colbert's crew finds a bonebed full of complete skeletons.

    People: George Whitaker, Edwin H. Colbert

  4. 2006 · Major study

    Coelophysis cannibalism refuted

    Nesbitt and colleagues show the gut contents are crocodylomorphs.

    People: Sterling J. Nesbitt, Mark A. Norell

Sources

  1. (2026). Paleobiology Database: Coelophysis bauri collections 48422 (Ghost Ranch) and 52498 (Arroyo Seco). The Paleobiology Database (paleobiodb.org), data service 1.2, accessed 2026-09-23. https://paleobiodb.org/data1.2/colls/list.json?coll_id=48422,52498&show=paleoloc,strat,loc,ref,geo&pgm=gplates&vocab=pbdb (opens in a new tab)
  2. (2026). Wikipedia: Coelophysis. Wikipedia (English), accessed 2026-09-24. https://en.wikipedia.org/wiki/Coelophysis (opens in a new tab)
  3. Colbert, E. H. (1947). The little dinosaurs of Ghost Ranch. Natural History 56(9).
  4. Cope, E. D. (1887). The dinosaurian genus Coelurus. American Naturalist 21: 367-369.
  5. Nesbitt, S. J., Turner, A. H., Erickson, G. M. & Norell, M. A. (2006). Prey choice and cannibalistic behaviour in the theropod Coelophysis. Biology Letters 2: 611-614. doi:10.1098/rsbl.2006.0524 (opens in a new tab)
  6. Paul, G. S. (2016). The Princeton Field Guide to Dinosaurs (2nd edition). Princeton University Press.