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Egg type

Megaloolithus

Mikhailov 1991

Megaloolithus 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 89.8–66 million years old in 5 countries, most often Spain and India.

Confidence labels
How sure are we?0 high26 medium5 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
89.8–66 Ma
Triassic
Jurassic
Cretaceous
252 million years ago20114366

Solid: the ages of its dated fossils, 89.8–66 million years ago (Omnisaura's calculation). Pale: the published range, 168.6–66 million years ago, which also counts records Omnisaura leaves out.

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
Mikhailov 1991
mediummedium: Only PBDB gives this; nothing contradicts it.
Sources

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

Described in
K. E. Mikhailov (1991). Classification of fossil eggshells of amniotic vertebrates. Acta Palaeontologica Polonica 36(2): 193–238.
mediummedium: Only PBDB gives this; its author and year match the naming authority (Mikhailov 1991).
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
Bajocian to Maastrichtian, 168.6–66 million years ago
mediummedium: Only PBDB gives this; nothing contradicts it.
Omnisaura calculation89.8–66 million years ago, from its dated fossil records
mediummedium: Omnisaura's calculation from 161 confirmed PBDB records.
Sources

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

Found in
Argentina
mediummedium: Only PBDB records it (12 records).
France
mediummedium: Only PBDB records it (48 records).
India
mediummedium: Only PBDB records it (46 records).
Morocco
mediummedium: Only PBDB records it (2 records).
Spain
mediummedium: Only PBDB records it (56 records).
Sources

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

Rock formations
20, including Lameta, Grey Garumnian, Allen and Lower Red Garumnian
mixedmixed: Levels differ between entries; each has its own.
Show all 20, each with its confidence
Allen
mediummedium: Only PBDB records it (6 records).
Anacleto
mediummedium: Only PBDB records it (6 records).
Argiles et Grès à Reptiles
mediummedium: Only PBDB records it (8 records).
Arén
mediummedium: Only PBDB records it (2 records).
Calcaire de Rognac
mediummedium: Only PBDB records it (2 records).
Conques
mediummedium: Only PBDB records it (3 records).
Figuerola
mediummedium: Only PBDB records it (2 records).
Grey Garumnian
mediummedium: Only PBDB records it (12 records).
Grès à Reptiles
mediummedium: Only PBDB records it (3 records).
Irbzer
mediummedium: Only PBDB records it (2 records).
La Posa
mediummedium: Only PBDB records it (5 records).
Lameta
mediummedium: Only PBDB records it (45 records).
Lower Red Garumnian
mediummedium: Only PBDB records it (14 records).
Marnes Rouges Inférieures
mediummedium: Only PBDB records it (2 records).
Villanueva de Huerva
mediummedium: Only PBDB records it (2 records).
Kallankurichchi
lowlow: Only one PBDB record.
La Maçana
lowlow: Only one PBDB record.
Marnes Rouges de Roquelongue
lowlow: Only one PBDB record.
Talarn
lowlow: Only one PBDB record.
Villalba de la Sierra
lowlow: Only one PBDB record.
Sources

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

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

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

Parent group
Megaloolithidae
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.
  • Held back: 19 fossil records 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); 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, 83.6 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.

FusioolithusHadrosauropodusPrismatoolithusRhabdodonCairanoolithusPararhabdodonIsisaurusNeuquensaurusAmpelosaurusAgeroolithusAntarctosaurusAustroraptorGasparinisauraPseudomegaloolithusRocasaurusSankofaand 27 more

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

Pictures linked from this page are credited beside each one, with their own licences; the full list is in the JSON download.