Dinosaur

Maiasaura peeblesorum

Good mother lizard

Maiasaura is the Two Medicine hadrosaur whose nesting colony at Egg Mountain, Montana, showed that dinosaurs cared for their young; it is Montana's state fossil. Bone from the Willow Creek anticline bonebeds and eggshell fragments reach the market from private land, but nest and embryo material is under research control. Eggshell has a characteristic nodular outer surface.

PhylumChordata
ClassReptilia
OrderOrnithischia
FamilyHadrosauridae
GroupDinosaur
Rank (PBDB)genus· Paleobiology Database
AuthorHorner and Makela 1979· Paleobiology Database
Classification (PBDB)Chordata › Ornithischia › NO_ORDER_SPECIFIED › Hadrosauridae· Paleobiology Database
Range (PBDB)83.6–72.2 Ma· Paleobiology Database
PBDB occurrences7· Paleobiology Database

Elsewhere

Cite this article

Stratum Study. "Maiasaura peeblesorum" (Taxon). Stratum Study pack 2026.09, as of 2026-09-19. https://stratum.black/study/taxa/maiasaura-peeblesorum. Accessed 2026-09-20.

@misc{stratum-maiasaura-peeblesorum,
  title        = {Maiasaura peeblesorum},
  author       = {{Stratum Study}},
  howpublished = {\url{https://stratum.black/study/taxa/maiasaura-peeblesorum}},
  year         = {2026},
  note         = {Taxon article, Stratum Study pack 2026.09, as of 2026-09-19; sources: stratum, pbdb, wikidata. Accessed 2026-09-20.}
}

Citations carry the pack version and the article's as-of date so they resolve to the same text later. The facts themselves belong to the sources listed below; cite those for the science.

Sources for this article: Stratum editorial (Stratum editorial);Paleobiology Database (CC-BY-4.0);Wikidata (CC0). As of 2026-09-19; Study pack 2026.09. Data reproduced under the licences shown; text in Stratum's own words unless a section names its source.

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