Dinosaur genus
Amargasaurus
Amargasaurus is a dinosaur genus known from bones, found in rocks 125.8–121.4 million years old, in Argentina.
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 11 October 2026- Named by
- Bonaparte 1984
disputed
low: PBDB and Wikidata agree on who named it but give years more than one apart; an editor has not ruled yet.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Described in
- J. F. Bonaparte (1984). I dinosauri dell’Argentina [. Sulle Orme dei Dinosauri: 125–143.
medium
medium: Only PBDB gives this; its author and year match the naming authority (Bonaparte 1984).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
- Barremian, 125.8–121.4 million years ago
medium
medium: Only PBDB gives this; nothing contradicts it.Omnisaura calculation125.8–121.4 million years ago, from its dated fossil recordslow
low: Omnisaura's calculation from only 2 dated record(s).Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Fossils found in
- Argentina
medium
medium: Only PBDB records it (2 records).Sources
Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).
- Rock formations
- La Amarga
medium
medium: Only PBDB records it (2 records).Sources
Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.
- Family
- Dicraeosauridae
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Parent group
- Dicraeosaurinae
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Named after
- La Amarga Formation
medium
medium: Only Wikidata gives this; nothing contradicts it.Sources
Given by: Wikidata. How it was chosen: Wikidata leads.
- Species named in its records
- Amargasaurus cazaui
Sources
Given by: Paleobiology Database (the species its fossil records are identified as).
- Diet
- herbivore (inferred for its group)
medium
medium: Only PBDB gives this, and it infers it for the whole of Sauropoda, the group this genus belongs to, not from this genus's own fossils.Sources
Given by: Paleobiology Database. How it was chosen: PBDB, inferred from a group the genus belongs to.
- Way of life
- ground dwelling, gregarious (inferred for its group)
low
low: PBDB infers this way of life for the whole of Sauropoda; behaviour is rarely known for one genus.Sources
Given by: Paleobiology Database. How it was chosen: PBDB, inferred from a group the genus belongs to.
- Known from
- Bones
Sources
Given by: Paleobiology Database (what the name was based on).
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.
- Resting on one source: 5 facts come from a single source with nothing against them (rated medium): parent group (PBDB); family (PBDB); age (headline) (PBDB); named after (Wikidata); diet (PBDB).
Size and appearance aren't covered yet, and diet and way of life only as PBDB infers them for the wider group. Omnisaura leaves the rest out rather than guess.
Where sources disagree
1 openAuthority
- Bonaparte 1984PBDB (shown above)
- Leonardo Salgado and José Bonaparte, 1991Wikidata
The sources agree on who named it but give different years. An editor hasn't ruled yet, so this is rated low until they do.
Did it meet…?
No. Amargasaurus had gone at least 37.8 million years before Tyrannosaurus appears in the fossil record.
Going by the ages and rock formations of their dated fossils, as on the map. Compare their fossil sites on the map.
Connections
Genera linked to Amargasaurus by where and when their fossils were found, by classification and by who named them. Select a name to open its page.
Same rocks, same time 1
Genera found in the same rock units, from rocks of overlapping age, the most shared fossil sites first.
Same family: Dicraeosauridae 6
Other genera in Dicraeosauridae with a full profile.
Named by Bonaparte 13
Genera whose naming authority includes the same surname. The authority has no initials, so different people who share a surname can appear together.
Found in Argentina 2
Other genera found in Argentina, from rocks of overlapping age, the most fossil sites there first.
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.