OBJECT DOSSIER · SMITHSONIAN OPEN ACCESS

Early dinosaur — Eoraptor lunensis

SAGE Museum Deep Time scientific dossier

Artist / Creator

Will Beckett

Date / Period

Late Triassic — Carnian · Approximately 232 to 231 million years ago according to the Smithsonian Deep Time interpretation.

Object Type

cast

Medium

cast

About This Object

Geologic period: Late Triassic — Carnian

Age: Approximately 232 to 231 million years ago according to the Smithsonian Deep Time interpretation.

Feeding: Smithsonian interprets Eoraptor as omnivorous. Its teeth include features consistent with a mixed diet.

Locomotion: Bipedal terrestrial locomotion.

Body plan: Lightly built bipedal dinosaur with a small skull, grasping forelimbs and relatively long hind limbs.

Evidence: Nearly complete skeletal material provides unusually detailed anatomical evidence for such an early dinosaur.

Why it matters: Eoraptor helps document the first major diversification of dinosaurs before they became dominant terrestrial animals.

Plain Language Identity: One of the earliest well-known dinosaurs, a small bipedal saurischian from Late Triassic Argentina.

What You Are Looking At: A skeletal cast based on fossils of Eoraptor lunensis.

Ecosystem: Ischigualasto Formation ecosystem of what is now Argentina.

Preservation: Visitor object is a cast based on fossil skeletal material.

Find Location: San Juan Province, Argentina.

Formation: Ischigualasto Formation.

Research History: Eoraptor was originally interpreted as an early theropod. Detailed later studies recovered it as an early sauropodomorph, and its placement has played an important role in debates over early dinosaur relationships.

Open Questions: Present Eoraptor securely as an early dinosaur while acknowledging the history of debate over its precise position within Saurischia.

Source Urls: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list; https://www.si.edu/newsdesk/factsheets/david-h-koch-hall-fossils-deep-time; https://doi.org/10.1080/02724634.2013.820113; https://doi.org/10.1080/14772019.2024.2345333

Enrichment Method: SAGE curated research pass; title and scientific name matched; chronology and lineage distinctions retained; evidence separated from inference

Scientific name: Eoraptor lunensis

Evidence / representation: comparative_taxon_visual

Why It Is In This SAGE Exhibit

comparative_taxon_visual

Rise of the Dinosaurs: A New World After Catastrophe.

Provenance

Smithsonian Deep Time source scene: Reptiles Move Back to the Ocean in the Jurassic

Visual source institution: Wikimedia Commons

Exhibition History

Included in the SAGE Museum Dinosaurs & Deep Time staging exhibit.

Collection & Credit

Media license: CC BY 2.0

https://creativecommons.org/licenses/by/2.0

Subjects & Themes

Eoraptor lunensis Late Triassic — Carnian cast Reptiles Move Back to the Ocean in the Jurassic Rise of the Dinosaurs

ORIGINAL COLLECTION SOURCE

This object page stays inside SAGE Museum. The Smithsonian link below is provided only as the original scholarly collection record. It opens separately.

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