EXPLORE PREHISTORY 240 prehistoric animal profiles · Scientific & movie-style image galleries
DinoGrove.
The collection/Haya

EXHIBIT 238

Haya

Haya griva

Dinosaur

Haya was a small Mongolian dinosaur known from detailed skulls, growing skeletons and stomach-stone associations. [1]

Evidence profile

TWO WAYS TO PICTURE THE PAST

Compare the evidence with the familiar movie image. The illustrations are not to a shared scale.

01 / SOURCE-INFORMED RECONSTRUCTION

A life reconstruction from the evidence

Illustrative life reconstruction of Haya in a period-appropriate environment; coloration and missing anatomy are interpretations.

An illustrative reconstruction. Compare its anatomy with the evidence and limitations in the dossier. [2]

Source-informed reconstruction. Appearance evidence [2]. Original illustration; missing anatomy, coloration and scenery include interpretation.

Fossils constrain this life reconstruction. Missing anatomy, coloration and the environmental scene include interpretation; the dossier explains the evidence limits.

02 / MOVIE-STYLE INTERPRETATION

A cinematic imagination

Illustrative reconstruction of Haya griva; missing anatomy, pose, skin and colors are hypotheses.

An illustrative reconstruction. Compare its anatomy with the evidence and limitations in the dossier. 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 Cretaceous[3]
DIETPlant feeding inferred; exact diet uncertainEvidence and uncertainty in the dossier
TOTAL LENGTHSee the dossierEstimate scope matters
FOSSILS FOUNDMongolia[1]
CompareRead the dossierView the sources

MEET THE ANIMAL

Meet Haya

Haya was a small, lightly built dinosaur from Mongolia, with an elongated head and a long tail. The detailed study of its skeletons gives researchers unusually rich anatomical information. Yet the known individuals were still growing. Even the larger sampled bones belonged to subadults, so scientists cannot simply call the biggest fossil the final adult size or use it to establish the species' maximum length. [D1]

The front of Haya's upper jaw carried small teeth, while other teeth farther back helped process food. Several skeletons also have clusters of swallowed stones near the abdomen. These discoveries are clues to feeding and digestion, although they do not preserve a complete daily menu. The hand bones are less complete than the skull, so illustrations must treat some finger details as restorations. [D2]

A recent study compared the shapes of dinosaur stomach stones with those of living birds. Haya was among the fossils examined, and its predicted diet differed from the usual plant-feeding interpretation. The researchers explain that stone shape is more directly a clue to how the stomach worked, and their models can misidentify diets. This leaves room for uncertainty instead of proving that Haya ate one particular food. [D4]

PREHISTORIC ANIMAL DOSSIER

A life in profile.

The animal, the evidence, and the questions still open.

Stomach stones offer clues to digestion, but a recent shape model does not establish an exact menu. [D4]

Profile scope: Genus — Haya griva; type IGM 100/2017 and referred juvenile-to-subadult material. [D1]

Time
Late Cretaceous
Fossil locations in this exhibit
Mongolia
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 length

Not established

Not established here

Known material is juvenile to subadult; mature body length remains unknown. [D1]

Body mass

Not established

Not established here

No mature specimen or comparable maturity-qualified body-mass estimate is adopted. [D1]

Diet and feeding

Debated

Plant feeding inferred; exact diet uncertain

Tooth wear supports oral processing. A gastrolith-shape model differs from conventional herbivory and has acknowledged predictive limits; no particular meal is known. [D4]

Habitat and setting

Inferred

Mongolian terrestrial deposits

Santonian–Campanian Javkhlant and correlated Zos records include river-deposited sediments. Modern desert geography is not automatically the animal's habitat. [D3]

Movement

Inferred

Slender bipedal reconstruction

Hindlimb and tail anatomy support two-legged movement; complete finger details remain uncertain. [D2]

Recognizable anatomy

Source supported

Elongated skull and front upper teeth

Small bulbous premaxillary teeth distinguish the snout from a large toothless upper beak; cheek teeth and slender limbs complete the profile. [D2]

Reproduction & life together

Reproduction and nesting

Not established

Not established here

The reviewed skeletons do not assign an egg or nest to Haya. [D2]

Mating and courtship

Not established

Not established here

Reviewed anatomy does not establish mating displays or sexual color differences. [D2]

Social behavior

Not established

Not established here

Multiple fossil individuals do not by themselves establish stable herds. [D2]

Dossier research & sources

Sources and inspection notes for the claims in this profile.

  1. The osteology of Haya griva (Dinosauria: Ornithischia) from the Late Cretaceous of Mongolia (Barta and Norell, 2021)Bulletin of the American Museum of Natural History 445:1–111 · Accessed 2026-10-06Full 114-page PDF retained and type, diagnoses, cranial/appendicular anatomy, gastroliths, histology and growth discussion inspected. IGM100/2017 type; entire sample juvenile–subadult, no skeletally mature individual. Phylogenetic placements within early neornithischians vary; no final adult size, longevity or mature morphology established. · Inspected: page
  2. A New Basal Ornithopod (Dinosauria, Ornithischia) from the Late Cretaceous of Mongolia (Makovicky et al., 2011)Journal of Vertebrate Paleontology 31(3):626–640; doi:10.1080/02724634.2011.557114 · Accessed 2026-10-06Original author-uploaded text inspected for type identity, skull/teeth, appendicular and manual anatomy, gastroliths and interpretation. Manual formula incompletely known; skull has small front upper teeth rather than a large upper keratin beak. Gastrolith presence alone does not identify every food. · Inspected: page
  3. A New Specimen of the Ornithischian Dinosaur Haya griva, Cross-Gobi Geologic Correlation, and the Age of the Zos Canyon Beds (Norell and Barta, 2016)American Museum Novitates 3851:1–19; doi:10.1206/3851.1 · Accessed 2026-10-06Original coauthor-uploaded text inspected, including IGM100/3181 identification, lithology and stratigraphic correlation. Santonian–Campanian correlation; Zos deposits include fluvial sands/channel deposits/fossil wood and lack the dominant aeolian component of adjacent younger Djadokhta beds. Burial setting constrains landscape but is not direct habitat preference. · Inspected: page
  4. Gastrolith shape as an indicator of digestive function and its implications for dinosaurian digestive strategies (2026)Paleobiology, Cambridge University Press · Accessed 2026-10-06Original Figure1, Haya specimen/table context, results and discussion inspected. Haya IGM100/2015 included; prediction differs from conventional herbivory. The authors emphasize mechanical digestive function, sample size, confounding stone properties and imperfect diet predictions. No actual Haya meal identified. · Inspected: excerpt

THE STORY IN THE FOSSILS

Evidence behind Haya

The detailed growth study contains no fully mature individual, so the size of the largest fossil is not declared an adult maximum. [1]

Correlated river deposits guide the landscape reconstruction; present-day Gobi dunes are not substituted for its ancient setting. [3]

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.

  1. The osteology of Haya griva (Dinosauria: Ornithischia) from the Late Cretaceous of Mongolia (Barta and Norell, 2021)Bulletin of the American Museum of Natural History 445:1–111 · Accessed 2026-10-06Full 114-page PDF retained and type, diagnoses, cranial/appendicular anatomy, gastroliths, histology and growth discussion inspected. IGM100/2017 type; entire sample juvenile–subadult, no skeletally mature individual. Phylogenetic placements within early neornithischians vary; no final adult size, longevity or mature morphology established. · Inspected: page
  2. A New Basal Ornithopod (Dinosauria, Ornithischia) from the Late Cretaceous of Mongolia (Makovicky et al., 2011)Journal of Vertebrate Paleontology 31(3):626–640; doi:10.1080/02724634.2011.557114 · Accessed 2026-10-06Original author-uploaded text inspected for type identity, skull/teeth, appendicular and manual anatomy, gastroliths and interpretation. Manual formula incompletely known; skull has small front upper teeth rather than a large upper keratin beak. Gastrolith presence alone does not identify every food. · Inspected: page
  3. A New Specimen of the Ornithischian Dinosaur Haya griva, Cross-Gobi Geologic Correlation, and the Age of the Zos Canyon Beds (Norell and Barta, 2016)American Museum Novitates 3851:1–19; doi:10.1206/3851.1 · Accessed 2026-10-06Original coauthor-uploaded text inspected, including IGM100/3181 identification, lithology and stratigraphic correlation. Santonian–Campanian correlation; Zos deposits include fluvial sands/channel deposits/fossil wood and lack the dominant aeolian component of adjacent younger Djadokhta beds. Burial setting constrains landscape but is not direct habitat preference. · Inspected: page
  4. Gastrolith shape as an indicator of digestive function and its implications for dinosaurian digestive strategies (2026)Paleobiology, Cambridge University Press · Accessed 2026-10-06Original Figure1, Haya specimen/table context, results and discussion inspected. Haya IGM100/2015 included; prediction differs from conventional herbivory. The authors emphasize mechanical digestive function, sample size, confounding stone properties and imperfect diet predictions. No actual Haya meal identified. · Inspected: excerpt

FOLLOW YOUR CURIOSITY

Who will you meet next?

KEEP EXPLORING

More from the collection

Scaly featherless raptor in a dark forest, with a long level tail, grasping hands and a raised curved toe claw.
Movie-style interpretation
Late Cretaceous

Velociraptor

Velociraptor mongoliensis

Velociraptor mongoliensis was a lightly built meat-eater from Late Cretaceous Mongolia. Its long limbs, teeth and enlarged foot claws made it distinctive, while the Fighting Dinosaurs specimen records a remarkable interaction with a horned dinosaur.

CarnivoreMeet this animal