SauropodomorphaApatosaurinaeApatosaurusNMST-PV 20375

Apatosaurus ajax

Apatosaurus ajax skeletal reconstruction, left lateral view, specimen NMST-PV 20375, reconstructed length ~18 m.
Scale bar = 1 meter
Taxon
Apatosaurus ajax Marsh, 1877
Specimen
NMST-PV 20375
Reconstructed length
~18 m (59 feet)
View
Left lateral
Drawing
© Scott Hartman
Drawn
2006, revised 2026
Clade
  1. Sauropodomorpha
  2. Sauropoda
  3. Neosauropoda
  4. Diplodocoidea
  5. Diplodocidae
  6. Apatosaurinae

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The type species of Apatosaurus, from the Late Jurassic Morrison Formation of the American West. While relatively heavily built for a diplodocid, with a deep, robust neck and tail, it was still not as heavily built as its relative, Apatosaurus louisae.

The evidence

What the specimen actually preserves

Known skeletal material of Apatosaurus ajax NMST-PV 20375: preserved elements shown in white against a black body silhouette.
Known material of NMST-PV 20375: elements preserved in the specimen are shown in white; unpreserved regions are left as black silhouette. Drawn 2006, revised 2026

Related reconstructions

Apatosaurus louisae skeletal reconstruction, left lateral view, specimen CM 3018, reconstructed length ~23 m.
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Apatosaurinae
Brontosaurus excelsus skeletal reconstruction, left lateral view, specimen CM 563, reconstructed length ~20 m.
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Barosaurus lentus skeletal reconstruction, left lateral view, specimen AMNH 6341, reconstructed length ~25 m.
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Diplodocus carnegii skeletal reconstruction, left lateral view, specimen CM 84, reconstructed length ~26 m.
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