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Egg type

Prismatoolithus

Zhao and Li 1993

Prismatoolithus 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 125.8–66 million years old in 9 countries, most often Spain and China.

Confidence labels
How sure are we?0 high20 medium14 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
125.8–66 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
Zhao and Li 1993
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Described in
Z.-K. Zhao, R. Li (1993). First record of Late Cretaceous hypsilophodontid eggs from Bayan Manduhu, Inner Mongolia. Vertebrata PalAsiatica 31(2): 77–84.
mediummedium: Only PBDB gives this; its author and year match the naming authority (Zhao and Li 1993).
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
Barremian to Maastrichtian, 125.8–66 million years ago
mediummedium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation125.8–66 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 53 confirmed PBDB records.
Sources

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

Found in
Canada
mediummedium: Only PBDB records it (8 records).
China
mediummedium: Only PBDB records it (9 records).
France
mediummedium: Only PBDB records it (10 records).
Japan
mediummedium: Only PBDB records it (2 records).
Spain
mediummedium: Only PBDB records it (13 records).
United States
mediummedium: Only PBDB records it (8 records).
Mexico
lowlow: Only one PBDB record.
Mongolia
lowlow: Only one PBDB record.
Russia
lowlow: Only one PBDB record.
mixedmixed: Levels differ between entries; each has its own.
Sources

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

Rock formations
19, including Conques, Chichengshan, North Horn and Two Medicine
mixedmixed: Levels differ between entries; each has its own.
Show all 19, each with its confidence
Chichengshan
mediummedium: Only PBDB records it (4 records).
Conques
mediummedium: Only PBDB records it (9 records).
Djadokhta
mediummedium: Only PBDB records it (2 records).
Figuerola
mediummedium: Only PBDB records it (2 records).
North Horn
mediummedium: Only PBDB records it (3 records).
Ohyamashimo
mediummedium: Only PBDB records it (2 records).
Oldman
mediummedium: Only PBDB records it (6 records).
Two Medicine
mediummedium: Only PBDB records it (4 records).
Blesa
lowlow: Only one PBDB record.
Dinosaur Park
lowlow: Only one PBDB record.
Dongyuan
lowlow: Only one PBDB record.
El Gallo
lowlow: Only one PBDB record.
Fruitland
lowlow: Only one PBDB record.
Horseshoe Canyon
lowlow: Only one PBDB record.
Ilek
lowlow: Only one PBDB record.
Majiacun
lowlow: Only one PBDB record.
Pingling
lowlow: Only one PBDB record.
Saint-Chinian
lowlow: Only one PBDB record.
Wulansuhai
lowlow: Only one PBDB record.
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.

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: Omnisaura editorial (Omnisaura editorial content (© Future Sailors, all rights reserved)), Paleobiology Database (CC BY 4.0), Natural History Museum Data Portal (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.
  • Held back: 5 fossil records left out: identified only tentatively (for example "cf." or "?").
  • Held back: 7 fossil records left out: identified as a related genus rather than this one.
  • 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, 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…?

?

Possibly. Both are recorded from the same rocks of the same age (Dinosaur Park), but there one of them is identified only to genus (for example from an isolated tooth).

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.

SaurornitholestesRichardoestesiaTroodonCentrosaurusParonychodonDromaeosaurusCorythosaurusChasmosaurusSpheroolithusContinuoolithusLambeosaurusAlbertosaurusElongatoolithusHypacrosaurusDaspletosaurusHadrosauropodusand 122 more

Same family

Other genera in Prismatoolithidae with a full profile.

PreprismatoolithusProtoceratopsidovumSankofaSpheruprismatoolithus

Credits

Where this page comes from