Omnisaura

Egg type

Spheruprismatoolithus

Bray 1999

Spheruprismatoolithus 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 the United States.

Confidence labels
How sure are we?0 high8 medium0 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 11 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
Bray 1999
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Described in
E. S. Bray (1999). Eggs and eggshell from the Upper Cretaceous North Horn Formation, central Utah. Vertebrate Paleontology in Utah, Utah Geological Survey Miscellaneous Publication 99-1: 361–375.
mediummedium: Only PBDB gives this; its author and year match the naming authority (Bray 1999).
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
mediummedium: Omnisaura's calculation from 3 confirmed PBDB records.
Sources

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

Found in
United States
mediummedium: Only PBDB records it (3 records).
Sources

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

Rock formations
North Horn
mediummedium: Only PBDB records it (3 records).
Sources

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

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

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

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

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

Species named in its records
Spheruprismatoolithus condensis, Spheruprismatoolithus condensus
Sources

Given by: Paleobiology Database (the species its fossil records are identified as).

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)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: 5 facts come from a single source with nothing against them (rated medium): name (PBDB); authority (PBDB); parent group (PBDB); family (PBDB); age (headline) (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

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.

Connections

Genera linked to Spheruprismatoolithus by where and when their fossils were found, by classification and by who named them. Select a name to open its page.

SpheruprismatoolithusFound in the same rocksSame familyAlso found in United StatesContinuoolithusAlamosaurusOvaloolithusPrismatoolithusand 1 morePreprismatoolithusProtoceratopsidovumSankofaand 1 moreTriceratopsTyrannosaurusEdmontosaurusThescelosaurusand 50 more

Found in the same rocks 5

Genera and other fossil types from the same rock units, from rocks of overlapping age, the most shared fossil sites first.

ContinuoolithusAlamosaurusOvaloolithusPrismatoolithusSpheroolithus

Same family: Prismatoolithidae 4

Other genera in Prismatoolithidae with a full profile.

PreprismatoolithusPrismatoolithusProtoceratopsidovumSankofa

Found in United States 54

Other genera found in United States, from rocks of overlapping age, the most fossil sites there first.

TriceratopsTyrannosaurusEdmontosaurusThescelosaurusParonychodonRichardoestesiaPachycephalosaurusAlamosaurusTroodonSaurornitholestesDromaeosaurusAnkylosaurusChirostenotesOrnithomimusGlyptodontopeltaEdmontoniaand 38 more

Credits

Where this page comes from

  • Paleobiology DatabaseCC BY 4.0 · fossil records, ages, classification
  • 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