Apatosaurus Size Comparison
Apatosaurus 3D Viewer pairs published A. ajax sauropod figures with a 1.8 m person on screen - length about 21 m on the NHM reference (average about 21-23 m; largest known near about 30 m), weight about 22.4 tonnes (average about 16.4-22.4 tonnes), and era 152-151 Mya - so the stocky scale gap stays readable at a glance.
Apatosaurus published figures
The Apatosaurus facts panel and this table disclose published ranges rather than one invented single number; the Size vs human control uses about 21 m as the length scale ratio:
| Measure | Figure | Vs a 1.8 m person |
|---|---|---|
| Length | about 21 m (NHM reference for A. ajax); average about 21-23 m across sources; largest known specimens up to about 30 m; Size vs human uses about 21 m | ~11.7x a person end-to-end at the 21 m scale figure |
| Height | about 4.2 m (model heightM used by the scene) | ~2.3x adult standing height |
| Weight | about 22.4 tonnes / 22400 kg (NHM); average about 16.4-22.4 tonnes; largest known up to about 33 tonnes | sources disagree by study - shown as a range with one NHM representative point |
| When it lived | 152-151 million years ago | late Kimmeridgian to early Tithonian, Late Jurassic; herbivore; named by Othniel Charles Marsh in 1877 (A. ajax); Morrison Formation, western North America; Brontosaurus named 1879, synonymized 1903, reinstated as a distinct genus in a 2015 diplodocid study (Tschopp et al.) |
How the Apatosaurus size-vs-human toggle stays honest
The Apatosaurus model is drawn to a fixed on-screen length so it fits the canvas; the Size vs human control then places a 1.8 m person at the true length ratio used by the viewer (about 21 m). Tap Size vs human under the canvas to show or hide the scale figure - the comparison is proportional, not a decorative sticker. Published length still spans about 21-23 m on average with largest known individuals near about 30 m, so the toggle picks the clear NHM 21 m scale inside that disclosed range. The shared sauropod builder does not use tallForelimbs (same branch as Diplodocus), so the silhouette stays the long-necked, long-tailed horizontal body; deeper neck vertebrae are described in the facts copy as supporting a heavier build than Diplodocus, not as a distinct mesh.
What a person would see beside an Apatosaurus
What a person would see is a quadrupedal sauropod whose body length at the 21 m scale dwarfs a 1.8 m adult end-to-end, with a stockier neck plan than Diplodocus and a whip-like counterweight tail - turn on the person in the viewer and orbit beside a hind leg to feel how the horizontal-back posture and shorter front legs sit relative to the scale figure. Skin and color are an artistic reconstruction, not a fossil-accurate skeleton. Click head, neck, body, leg, or tail in the viewer for the fossil facts tied to those parts.
What the Apatosaurus size numbers are not
What these size numbers are not is a claim of one precise length or weight beyond the cited ranges: the Apatosaurus size comparison discloses the NHM 21 m / 22.4 tonne reference inside the wider published averages and largest-specimen figures; it does not treat the Apatosaurus/Brontosaurus naming history as more settled than the cited 1903 / 2015 chronology, does not invent a distinct render geometry from Diplodocus, does not invent soft-tissue or color accuracy, no free-licensed Apatosaurus glTF is re-hosted yet so the viewer stays procedural, and this is not a win/lose game. For the control walkthrough see how to view Apatosaurus in 3D. For trade-offs versus phone AR apps see Apatosaurus 3D viewer vs AR apps.
Other dinosaurs to compare
Other dinosaurs in the collection make useful size comparisons too: Apatosaurus is a Late Jurassic Morrison Formation sauropod, so for a longer, lighter diplodocid see the Diplodocus 3D Viewer, or for a taller giraffe-like sauropod see the Brachiosaurus 3D Viewer.
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