Egg type

Placoolithus

Zhao 1979

Placoolithus 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 89.8–83.6 million years old in China.

Confidence labels

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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

89.8–83.6 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 1979
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Described in: Z. Zhao (1979). [Advances in the study of fossil dinosaur eggs in our country]. Mesozoic and Cenozoic red beds of South China; selected papers from the field conference on the South China Cretaceous-Early Tertiary red beds. Science Press, Beijing: 330–340.
medium
medium: Only PBDB gives this; its author and year match the naming authority (Zhao 1979).
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: Placoolithus taohensis
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Dated to: Coniacian to Santonian, 89.8–83.6 million years ago
medium
medium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation89.8–83.6 million years ago, from its dated fossil records
medium
medium: Omnisaura's calculation from 4 confirmed PBDB records.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Found in: China
medium
medium: Only PBDB records it (4 records).
Sources
Given by: Paleobiology Database. How it was chosen: Union of all sources (ISO 3166).
Rock formations: Gaogou
medium
medium: Only PBDB records it (3 records).
Majiacun
low
low: Only one PBDB record.
mixed
mixed: Levels differ between entries; each has its own.
Sources
Given by: Paleobiology Database. How it was chosen: Canonical names, automatic and editor-approved matches applied.
Egg family: Dendroolithidae
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Parent group: Dendroolithidae
medium
medium: Only PBDB gives this; nothing contradicts it.
Sources
Given by: Paleobiology Database. How it was chosen: PBDB leads.
Species named in its records: Placoolithus taohensis
Sources
Given by: Paleobiology Database (the species its fossil records are identified as).
Older or other names: Paradendroolithus (a junior synonym)
Sources
Given by: Paleobiology Database (names it treats as this genus).
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.
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: 6 facts come from a single source with nothing against them (rated medium): name (PBDB); authority (PBDB); type species (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…?

Did Placoolithus meet ?

No. Placoolithus had gone at least 0 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 Placoolithus by where and when their fossils were found, by classification and by who named them. Select a name to open its page.

Found in the same rocks 9

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

Elongatoolithus Ovaloolithus Paraspheroolithus Dendroolithus Faveoloolithus Nanhsiungoolithus Prismatoolithus Protodictyoolithus Spheroolithus

Named by Zhao 14

Genera whose naming authority includes the same surname. The authority has no initials, so different people who share a surname can appear together.

Changdusaurus Chaoyangsaurus Dendroolithus Dictyoolithus Elongatoolithus Faveoloolithus Macroolithus Nanhsiungoolithus Ovaloolithus Paraspheroolithus Prismatoolithus Shixingoolithus Sinraptor Spheroolithus

Found in China 28

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

Elongatoolithus Dendroolithus Paraspheroolithus Ovaloolithus Brontopodus Spheroolithus Faveoloolithus Macroelongatoolithus Macroolithus Protodictyoolithus Saichania Bactrosaurus Baotianmansaurus Chilantaisaurus Coralloidoolithus Hadrosauropodusand 12 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