OBJECT DOSSIER · SMITHSONIAN OPEN ACCESS

Phytosaur, crocodile-like reptile — Smilosuchus gregorii

SAGE Museum Deep Time scientific dossier

Artist / Creator

mark byzewski

Date / Period

Late Triassic · Approximately 213 to 209 million years ago according to Smithsonian's Deep Time factsheet.

Object Type

skeleton / skull / armor

Medium

unknown_needs_review

About This Object

Geologic period: Late Triassic

Age: Approximately 213 to 209 million years ago according to Smithsonian's Deep Time factsheet.

Feeding: Predatory.

Locomotion: Semiaquatic locomotion combined with movement on land.

Body plan: Large elongated body, armored back, powerful tail and long narrow snout.

Evidence: Skull, teeth, skeleton and armor provide direct evidence. Semiaquatic ambush behavior is inferred from anatomy and ecological context.

Why it matters: Smilosuchus is a spectacular example of convergent evolution: it looked broadly crocodile-like, but phytosaurs and crocodilians evolved those features independently.

Plain Language Identity: A large Late Triassic phytosaur that independently evolved a crocodile-like body and semiaquatic lifestyle.

What You Are Looking At: Fossil material representing the skull, skeleton and dermal armor of Smilosuchus gregorii.

Defense Or Attack: Long tooth-bearing jaws formed the primary prey-capture system.

Ecosystem: Late Triassic rivers and floodplains of western North America.

Preservation: Fossil skull, skeleton and armor.

Formation: Chinle Formation.

Find Location: Arizona, United States.

Research History: The Smithsonian specimen preserves pathology in the right lower jaw, offering evidence of injury or disease during the animal's life.

Open Questions: Never call Smilosuchus a crocodile. It was a phytosaur and represents a separate archosauriform lineage.

Source Urls: https://naturalhistory.si.edu/visit/virtual-tour/current-exhibits/deep-time-virtual-tour-fossil-list; https://www.si.edu/object/smilosuchus-gregorii-camp-1930:nmnhpaleobiology_3451097; https://www.si.edu/newsdesk/factsheets/david-h-koch-hall-fossils-deep-time

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

Scientific name: Smilosuchus gregorii

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

Smilosuchus gregorii Late Triassic skeleton / skull / armor 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.

VIEW ORIGINAL SMITHSONIAN RECORD ↗