Omnisaura

Egg type

Arriagadoolithus

Agnolin et al. 2012

Arriagadoolithus is an egg type: the name is for the fossil eggs themselves. The animal that laid them is not known for certain. Its eggs are found in rocks 72.2–66 million years old in Argentina.

Confidence labels
How sure are we?0 high5 medium3 lowHow we rate confidence

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
72.2–66 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
Agnolin et al. 2012
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Described in
F. L. Agnolin, J. E. Powell, F. E. Novas, M. Kundrát (2012). New alvarezsaurid (Dinosauria, Theropoda) from uppermost Cretaceous of north-western Patagonia with associated eggs. Cretaceous Research 35(1): 33–56. Read it
mediummedium: Only PBDB gives this; its author and year match the naming authority (Agnolin et al. 2012).
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.

Dated to
Maastrichtian, 72.2–66 million years ago
mediummedium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation72.2–66 million years ago, from its dated fossil records
lowlow: Omnisaura's calculation from only 1 dated record(s).
Sources

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

Found in
Argentina
lowlow: Only one PBDB record.
Sources

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

Rock formations
Allen
lowlow: Only one PBDB record.
Sources

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

Egg family
Arriagadoolithidae
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

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

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

Known from
Eggs
Sources

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

Laid by
Not known for certain. Eggs rarely show which animal laid them.
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

  • The animal that laid them: not known for certain, as for most egg types.
  • 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, 72.2 to 66 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.

Found in the same rocks

Genera and other fossil types from the same formations, from rocks of the same age.

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