Egg type
Tristraguloolithus
Tristraguloolithus 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 83.6–72.2 million years old in Canada.
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- Named by
- Zelenitsky et al. 1996
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Described in
- D. K. Zelenitsky, L. V. Hills, P. J. Currie (1996). Parataxonomic classification of ornithoid eggshell fragments from the Oldman Formation (Judith River Group; Upper Cretaceous), southern Alberta. Canadian Journal of Earth Sciences 33: 1655–1667. Read it
medium
medium: Only PBDB gives this; its author and year match the naming authority (Zelenitsky et al. 1996).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.
- Type species
- Tristraguloolithus cracioides
medium
medium: Only PBDB gives this; nothing contradicts it.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Dated to
- Campanian, 83.6–72.2 million years ago
medium
medium: Only PBDB gives this; nothing contradicts it.Omnisaura calculation83.6–72.2 million years ago, from its dated fossil recordsmedium
medium: Omnisaura's calculation from 3 confirmed PBDB records.Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
- Found in
- Canada
medium
medium: Only PBDB records it (3 records).Sources
Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).
- Rock formations
- Oldman
medium
medium: Only PBDB records it (3 records).Sources
Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.
- Parent group
- Theropoda
medium
medium: 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.
Gaps are answers
What isn't known yet
- The animal that laid them: not known for certain, as for most egg types.
- Order: no source we use gives it yet.
- Family: 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.
- Held back: 1 fossil record left out: identified only tentatively (for example "cf." or "?").
- Resting on one source: 4 facts come from a single source with nothing against them (rated medium): authority (PBDB); type species (PBDB); parent group (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.
Found in the same rocks
Genera and other fossil types from the same formations, from rocks of the same age.
Same parent group
Other genera in Theropoda with a full profile.
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