Edmontosaurus
Hadrosaurid dinosaur genus from Late Cretaceous US and Canada
Edmontosaurus, often colloquially and historically known as Anatosaurus or Anatotitan, is a genus of hadrosaurid (duck-billed) dinosaur. It contains two known species: Edmontosaurus regalis and Edmontosaurus annectens. Fossils of E. regalis have been found in rocks of western North America that date from the late Campanian age of the Cretaceous period 73 million years ago, while those of E. annectens were found in the same geographic region from rocks dated to the end of the Maastrichtian age, 66 million years ago. Edmontosaurus was one of the last non-avian dinosaurs ever to exist, and lived alongside dinosaurs like Triceratops, Tyrannosaurus, Ankylosaurus, and Pachycephalosaurus shortly before the Cretaceous–Paleogene extinction event.
Begin with the source’s own compact description: “Edmontosaurus” is hadrosaurid dinosaur genus from Late Cretaceous US and Canada. The dossier treats that line as a proposition to test through Edmontosaurus, Hadrosaurid and dinosaur, not as a finished interpretation.
Why this record matters
The phrase “hadrosaurid dinosaur genus from Late Cretaceous US and Canada” supplies a clear boundary for inquiry. It also exposes the unanswered questions: who defined that boundary, when it became stable and which sources sit outside it.
The date and method of observation matter as much as the stated conclusion, especially where classification or consensus has changed. The source revision retrieved here is dated Aug 29, 2026.
Current terminology should not be projected backward without checking the classification used when the underlying evidence was created. The lead is largely declarative, so disagreement and counter-evidence require a deliberate search beyond the opening account. Authority statements aid reconciliation but still require their own references, qualifiers and ranks to be checked.
How to read it
Check terminology, classification and the date of the cited evidence. Scientific names and technical consensus can change while older records retain historical value.
- Current terminology
- Classification context
- Finding cited technical literature
Primary datasets, specimen catalogues, standards bodies and the most recent peer-reviewed literature.
Three-step research path
- Establish the record: confirm the title “Edmontosaurus”, its source revision and the description used here.
- Expand the search: follow Edmontosaurus primary sources, Edmontosaurus archive and Edmontosaurus research across catalogues and specialist indexes.
- Test the account: compare the strongest cited source with the responsible institution’s current record and note any disagreement.
Questions for further research
- Which source most directly establishes the central claim about “Edmontosaurus”?
- Which observation, specimen, dataset or publication supports the account?
- Is the terminology current, historical or disputed?
Search terms from this dossier
This entry incorporates text from “Edmontosaurus” on English Wikipedia. Contributors are listed in the page history. Text is available under the Creative Commons Attribution-ShareAlike 4.0 License. Selected authority identifiers and statements are retrieved from Wikidata under CC0; their references and qualifiers remain part of the verification path.