Body length
InferredAbout 2 m (growing individual)
Institutional reconstruction of a juvenile; adult maximum is unestablished. [D3]
EXHIBIT 157
Tawa
Tawa hallae
Tawa combined a long snout, slender limbs and a hand with three functional fingers. [1]
TWO WAYS TO PICTURE THE PAST
Science & the silver screen
Compare the evidence with the familiar movie image. The illustrations are not to a shared scale.
01 / SKELETAL RECONSTRUCTION
A framework from the fossils
Image unavailableTawa hallae skeletal reconstruction with known bones in white and missing bones in grey.The exhibit and its credited image source remain available.
Tawa hallae known-material reconstruction by Maurissauro. White bones represent known material and grey bones complete missing regions; the surrounding outline and posture are hypothetical. The drawing combines the available skeletal evidence rather than documenting one complete adult individual, skin covering or an adult maximum. [1]
Tawa hallae skeleton.png · Maurissauro. CC BY-SA 4.0. Current Commons 1280 px preview converted to WebP and proportionally reduced for thumbnail use. No cropping, mirroring, anatomical edits or compositing; original scale bars retained. Derivatives retain CC BY-SA 4.0.
Skeletal mounts and drawings may restore missing parts; the caption identifies the displayed material.
02 / MOVIE-STYLE INTERPRETATION
A cinematic imagination
Image unavailableIllustrative reconstruction of Tawa hallae; missing anatomy, covering and colors are hypotheses.The exhibit and its credited image source remain available.
Original cinematic interpretation of Tawa. A lightly built reconstruction guided by preserved Tawa material; fine external covering, colors and posture are interpretive. Lighting, colors and scenery are artistic choices; this image does not document directly observed behavior. Lighting, coloration and scenery are artistic choices. This image does not document a fossil locality or behavior.
Original artwork · artistic interpretation.
Scientific view: source-informed reconstruction, credited paleoart or specimen-based imagery. Movie-style view: Original artistic interpretation. Reconstructions involve uncertainty.
PERIODLate Triassic[1]
DIETCarnivoreEvidence and uncertainty in the dossier
TOTAL LENGTHSee the dossierEstimate scope matters
FOSSILS FOUNDUSA[1]
MEET THE ANIMAL
Meet Tawa
Tawa was a carnivorous dinosaur from Late Triassic New Mexico. An institutional account reconstructed a growing individual at about two metres long. That is useful for imagining this particular animal, but does not tell us the maximum size of an adult Tawa. A juvenile reconstruction needs to be distinguished from a species-wide size range and from estimates based on other, separately identified fossils. [D3]
Researchers reconstructed its forelimb muscles by studying bone attachment sites and comparing living relatives of dinosaurs. The result suggests a hand capable of strong grasping. Besides three main fingers, the hand retained a strongly reduced fourth digit. Such anatomy tests what the arms could do; it does not preserve a hunting event or identify the exact prey being held. [D2]
The main skeleton was still growing, as indicated by open joins between parts of its vertebrae. Several skeletons accumulated in one small pocket of rock. Their proximity alone does not prove coordinated hunting, family relationships or a permanent social group. [D1]
PREHISTORIC ANIMAL DOSSIER
A life in profile.
The animal, the evidence, and the questions still open.
A 2026 analysis groups it with Chindesaurus and Daemonosaurus in Morphoraptora; their deeper relationships remain uncertain. [D5]
Profile scope: Genus — Tawa; profile centered on T. hallae and its separately identified specimens. [D1]
- Time
- Late Triassic
- Fossil locations in this exhibit
- USA
How to read the evidence
Source supported identifies a description documented by the cited source. Inferred marks a reconstruction or functional estimate. Debated marks competing interpretations. Not established means the sources reviewed for this dossier do not support a firm conclusion; it does not mean a behavior never occurred.
A size reference is an estimate, not a population range. Nesting evidence does not by itself establish courtship, mate choice, or lifelong pairing.
Body mass
InferredAbout 3.7 kg (limb model)
Isolated GR 244 femur; estimated circumference, maturity unestablished. [D4]
Diet and feeding
InferredAnimal prey inferred
Theropod-like dentition supports carnivory. Front premaxillary teeth are unserrated; particular prey and hunting tactics are unverified. [D1]
Habitat and setting
Source supportedChinle Formation, New Mexico
Hayden Quarry 2, lower Petrified Forest Member; isotopic age approximately 211.9±0.7 million years ago. [D1] [D5]
Movement
InferredTwo-legged; grasping forelimbs inferred
Forelimb muscle reconstruction supports forceful digital flexion. This establishes functional potential rather than observed prey handling or a measured running speed. [D2]
Recognizable anatomy
Source supportedThree main fingers; strongly reduced fourth
A slender skeleton combines a long neck and snout with an elongated first metatarsal; the fifth manual digit is absent. [D1]
Reproduction & life together
Reproduction and nesting
Not establishedNot established here
GR 241 was still growing, based on open sutures and larger referred bones. Neither breeding age nor nests are established. [D1]
Mating and courtship
Not establishedNot established here
Reconstructed forelimb muscles do not demonstrate a display, sex difference or mating sequence. Focused searches found no direct courtship evidence. [D2]
Social behavior
Not establishedNot established here
Several associated skeletons accumulated in one small pocket. Fossil proximity alone does not establish a social group, coordinated hunting or family association. [D1]
Dossier research & sources
Sources and inspection notes for the claims in this profile.
- A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs (Nesbitt et al., 2009)Science · Accessed 2026-10-02Original article and supporting material inspected in the author-paper PDF mirrored at jurassic-world.com: GR 241 is juvenile/subadult; separate GR 244 is an isolated femur. Hayden Quarry, lower Petrified Forest Member, Chinle Formation, New Mexico; historical 2009 estimate approximately 215–213 Ma, superseded by the reviewed later isotopic age. · Inspected: page
- Complete forelimb myology of the basal theropod dinosaur Tawa hallae based on a novel robust muscle reconstruction method (Burch, 2014)Journal of Anatomy · Accessed 2026-10-02Original abstract, methods and functional discussion inspected: musculature reconstructed through living-archosaur comparisons. Bipedal anatomy and grasping capacity are inferred; a fourth reduced manual digit is present. · Inspected: page
- Early carnivorous dinosaurs crossed continents (University of Utah, 2009)University of Utah institutional release via EurekAlert · Accessed 2026-10-02Indexed institutional release inspected: approximately 2 m juvenile reconstruction, not an adult maximum; new carnivorous dinosaur from New Mexico. · Inspected: excerpt
- Rates of dinosaur body mass evolution indicate 170 million years of sustained ecological innovation on the avian stem lineage (Benson et al., 2014), Dataset S1PLOS Biology · Accessed 2026-10-02Original XLS inspected: isolated GR 244 femur, 125 mm length; femoral circumference estimated from published diameters, giving 3.73977 kg. The dataset does not establish adulthood. · Inspected: page
- A new taxon of saurischian dinosaur from the Coelophysis Quarry of New Mexico, USA (Triassic: latest Norian or Rhaetian) highlights herrerasaurian diversity in the latest Triassic (Srivastava and Nesbitt, 2026)Papers in Palaeontology · Accessed 2026-10-02Original full systematics and phylogenetic discussion inspected: Morphoraptora hypothesis includes Tawa, Chindesaurus and Daemonosaurus; Ptychotherates and Chindesaurus types lack anatomical overlap. Distinct stratigraphic horizons support their separate naming, not a settled synonym. Locality section reports Hayden Quarry 2 isotopic age approximately 211.9±0.7 Ma. · Inspected: page
THE STORY IN THE FOSSILS
A hand reconstructed through anatomy.
Burch reconstructed missing muscles by comparing attachment evidence with living archosaurs. The result tests how the hand could function, without documenting a hunting event. [2]
The 2026 Morphoraptora proposal revisits the early dinosaur family tree; it does not merge these separately diagnosed genera. [5]
A note on scale and time
The dossier identifies the scope of each reference estimate. A mount, an individual fossil and a species-wide adult range are different measurements. Comparison metrics remain unavailable where adult scope has not been established. Unknown does not mean zero.
Sources & editorial notes
Sources support the stated claims and scopes. Refer to the evidence notes for uncertainty.
- A Complete Skeleton of a Late Triassic Saurischian and the Early Evolution of Dinosaurs (Nesbitt et al., 2009)Science · Accessed 2026-10-02Original article and supporting material inspected in the author-paper PDF mirrored at jurassic-world.com: GR 241 is juvenile/subadult; separate GR 244 is an isolated femur. Hayden Quarry, lower Petrified Forest Member, Chinle Formation, New Mexico; historical 2009 estimate approximately 215–213 Ma, superseded by the reviewed later isotopic age. · Inspected: page
- Complete forelimb myology of the basal theropod dinosaur Tawa hallae based on a novel robust muscle reconstruction method (Burch, 2014)Journal of Anatomy · Accessed 2026-10-02Original abstract, methods and functional discussion inspected: musculature reconstructed through living-archosaur comparisons. Bipedal anatomy and grasping capacity are inferred; a fourth reduced manual digit is present. · Inspected: page
- Early carnivorous dinosaurs crossed continents (University of Utah, 2009)University of Utah institutional release via EurekAlert · Accessed 2026-10-02Indexed institutional release inspected: approximately 2 m juvenile reconstruction, not an adult maximum; new carnivorous dinosaur from New Mexico. · Inspected: excerpt
- Rates of dinosaur body mass evolution indicate 170 million years of sustained ecological innovation on the avian stem lineage (Benson et al., 2014), Dataset S1PLOS Biology · Accessed 2026-10-02Original XLS inspected: isolated GR 244 femur, 125 mm length; femoral circumference estimated from published diameters, giving 3.73977 kg. The dataset does not establish adulthood. · Inspected: page
- A new taxon of saurischian dinosaur from the Coelophysis Quarry of New Mexico, USA (Triassic: latest Norian or Rhaetian) highlights herrerasaurian diversity in the latest Triassic (Srivastava and Nesbitt, 2026)Papers in Palaeontology · Accessed 2026-10-02Original full systematics and phylogenetic discussion inspected: Morphoraptora hypothesis includes Tawa, Chindesaurus and Daemonosaurus; Ptychotherates and Chindesaurus types lack anatomical overlap. Distinct stratigraphic horizons support their separate naming, not a settled synonym. Locality section reports Hayden Quarry 2 isotopic age approximately 211.9±0.7 Ma. · Inspected: page
KEEP EXPLORING
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