Omnisaura
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Dinosaur genus

Lewisuchus

Romer 1972

Lewisuchus is a dinosaur genus known from bones, found in rocks 241.5–72.2 million years old, in Argentina.

Confidence labels
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Confidence labels are switched off. Facts with low confidence, or where sources disagree, still carry a small dot: tap it for the reason.

At a glance

Data as of 12 October 2026
241.5–72.2 Ma
Triassic
Jurassic
Cretaceous
252 million years ago20114366

The last non-bird dinosaurs died out 66 million years ago. That's as far from us as the end of this bar.

Named by
Romer 1972
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB leads.

Described in
A. S. Romer (1972). The Chañares (Argentina) Triassic reptile fauna; XIV, Lewisuchus admixtus, gen. et sp. nov., a further thecodont from the Chañares beds. Breviora 390: 1–13.
mediummedium: Only PBDB gives this; its author and year match the naming authority (Romer 1972).
Sources

Given by: Paleobiology Database. The publication the Paleobiology Database gives as the authority for this genus name, usually the one that first named and described it.

Lived
Ladinian to Carnian, 241.5–233.6 million years ago
mediummedium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation241.5–72.2 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 4 confirmed PBDB records.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB leads.

Fossils found in
Argentina
mediummedium: Only PBDB records it (4 records).
Sources

Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).

Rock formations
Chañares
mediummedium: Only PBDB records it (4 records).
Sources

Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.

Family
Silesauridae
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB leads.

Parent group
Silesauridae
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

Given by: Paleobiology Database. How it was chosen: PBDB leads.

Known from
Bones
Sources

Given by: Paleobiology Database (what the name was based on).

Sources: Paleobiology Database (CC BY 4.0), Wikidata (CC0 1.0)Confidence levels and gaps are Omnisaura's own assessment.

Gaps are answers

What isn't known yet

  • Type species: no source we use gives it yet.
  • Order: no source we use gives it yet.
  • Common names: no source we use gives it yet.
  • What it was named after: no source we use gives it yet.
  • Resting on one source: 4 facts come from a single source with nothing against them (rated medium): authority (PBDB); parent group (PBDB); family (PBDB); age (headline) (PBDB).

Size, diet and behaviour aren't covered yet. Omnisaura leaves them out rather than guess.

Where sources disagree

None open. Where our sources overlap, they agree on everything shown here.

Did it meet…?

?

Same time, different places. Their fossils overlap in age, 83.6 to 72.2 million years ago, but no rock formation holds both.

Going by the ages and rock formations of their dated fossils, as on the map. Compare their fossil sites on the map.

Lived alongside

Genera found in the same rock formations, from rocks of the same age.

None in Omnisaura yet.

Same family

Other genera in Silesauridae with a full profile.

AmanasaurusAsilisaurusEucoelophysisKwanasaurusSilesaurus

Credits

Where this page comes from

  • Paleobiology DatabaseCC BY 4.0 · fossil records, ages, classification
  • WikidataCC0 1.0 · names and identifiers
  • OmnisauraOmnisaura editorial · confidence levels and gaps
  • PaleoMAP PaleoCoastlines (Kocsis and Scotese 2021)CC BY 4.0 · ancient coastlines on the small map
  • Natural EarthPublic domain · today's coastlines

Pictures linked from this page are credited beside each one, with their own licences; the full list is in the JSON download.