Binomial Apatosaurus ajax · uh-PAT-oh-SOR-us
Late Jurassic · 155-145 Ma
AI reconstructionApatosaurus fossil records in Fossil Atlas are mapped as selected modern discovery locations, with 64 source-backed records currently shown. Known from the Morrison Formation of the western United States, with important sauropod skeletons from Colorado, Utah, Wyoming, and nearby regions. Key mapped formations in the current dataset include Morrison Formation, Morrison Fm, Morrison. These pins are fossil record locations, not a complete ancient habitat map.
This remains a specimen profile: the reconstruction, measurements, field account, and evidence sections stay intact. The fossil-map answer is surfaced here so visitors from search can orient themselves before reading the full dossier.
Apatosaurus was a massive sauropod from the Late Jurassic Morrison Formation. It shares the Morrison stage with Stegosaurus, Allosaurus, and Diplodocus, but its proportions were more robust than the especially long Diplodocus. Fossil Atlas maps selected discovery records and keeps the evidence distinct from the AI reconstruction.
Drawn true to scale on a metre ruler.
Length
measured22 m · 72 ft
Largest known specimens
Height
measured5.5 m · 18 ft
Body mass
estimate22,000 kg · 48,500 lb
Typical adult
Top speed
estimate13 km/h · 8 mph
Modelled, debated
Teeth
measured≈ 60
Brain : body (EQ)
estimate0.2
Encephalization quotient
Position of this animal’s known range across 252 million years of the Mesozoic and beyond.
155-145 million years ago
Apatosaurus was more heavily built than Diplodocus.
The name means deceptive lizard, a nod to confusing vertebrae anatomy.
It is central to the public story behind the old Brontosaurus debate.
Apatosaurus helps turn the Morrison page into a true sauropod comparison set.
Pins show selected fossil records for Apatosaurus; use them as modern discovery evidence, not a complete range map. Modern fossil discovery map: pins show where selected fossil and specimen records were found today, not ancient Earth positions. What does this mean?
Specimen evidence
These are sourced specimen assets, separate from the AI reconstruction. Only media with clear open or reusable rights is displayed by default.
Apatosaurus sp. (YPM VP 004832). Digital Image: Yale Peabody Museum; photo by Division of Vertebrate Paleontology, Yale Peabody Museum 2016
Division of Vertebrate Paleontology, Yale Peabody Museum
Apatosaurus sp. (YPM VP 004832). Digital Image: Yale Peabody Museum; photo by Division of Vertebrate Paleontology, Yale Peabody Museum 2016
Division of Vertebrate Paleontology, Yale Peabody Museum
Apatosaurus (YPM VP 004689). Digital Image: Yale Peabody Museum; photo by Division of Vertebrate Paleontology, Yale Peabody Museum 2016
Division of Vertebrate Paleontology, Yale Peabody Museum
Apatosaurus sp. (YPM VP 004832). Digital Image: Yale Peabody Museum; photo by Division of Vertebrate Paleontology, Yale Peabody Museum 2016
Division of Vertebrate Paleontology, Yale Peabody Museum
Apatosaurus is represented here by selected fossil records from known from the morrison formation of the western united states, with important sauropod skeletons from colorado, utah, wyoming, and nearby regions. Fossil Atlas maps those records as modern discovery locations.
No. The map shows modern fossil discovery locations from selected records. Ancient habitat and paleogeographic reconstructions are separate questions.
The current Fossil Atlas records include Morrison Formation. Formation coverage depends on the selected dataset and may not be complete.
Yes. Use the expedition card generator to turn the Apatosaurus map and specimen profile into a shareable card.
Selected fossil records from PBDB and museum biodiversity aggregators. Source labels and confidence notes help distinguish canonical paleobiology records from specimen-media records.
Reconstruction images are labeled illustrations and do not represent fossil evidence. Size, speed, and bite-force figures are typical published estimates and remain subject to revision as new specimens are described.
Maps use curated PBDB, museum, and specimen-source records with visible caveats.
Pins show where fossils were found or reported today, not exact ancient habitat positions.
Artwork is labeled separately from specimen photos, maps, and source records.
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