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Diplodocus, Late JurassicMorrison Formation, Wyoming · named 1878
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Diplodocus

dih-PLOD-uh-kus

"double beam"

Type species Diplodocus longus

Lived
155 to 143 million years ago, Late Jurassic
Diet
Herbivore
Length
about 26 m (85 ft)
Weight
about 13 metric tons (14 short tons)
Group
Sauropods, Diplodocidae
Found in
United States
Named by
Marsh 1878

Size comparison

To scale

Where its fossils were found

The evidence

Today

62 finds

150 million years ago

Map: C. R. Scotese, PALEOMAP

Habitat

Rivers crossed broad Morrison floodplains, with conifers, ferns and horsetails. Stegosaurus, Camptosaurus and Dryosaurus lived in the same region.

Field notes

About Diplodocus

A body built for length

Diplodocus was one of the longest dinosaurs known, stretching about 26 meters, or roughly 85 feet, from its small head to the tip of its whip-like tail. It may have weighed around 13,000 kilograms, but most of its length was neck and tail rather than body. Its skull was long and low, with peg-shaped teeth at the front for stripping leaves off branches, and its nostrils sat high on its head. Despite its size, its bones were lightly built, with air spaces that kept the skeleton lighter than it looks.

Its world

Diplodocus lived during the Late Jurassic, between about 155 and 143 million years ago, across what is now Wyoming, Colorado, Utah, Oklahoma, Montana, and New Mexico. It is known from 62 separate fossil finds, most of them from the Morrison Formation, one of the richest fossil beds from this period. Diplodocus shared its world with fellow sauropods Brontosaurus, Apatosaurus, Brachiosaurus, and Camarasaurus, the armored Stegosaurus, and predators such as Allosaurus, Ceratosaurus, and Torvosaurus.

How it was found

Marsh named Diplodocus in 1878, taking the name from the double-beamed chevron bones under its tail. The type species is Diplodocus longus. With dozens of fossil finds to work from, Diplodocus is among the best-studied sauropods known today.

Field gallery

More views of Diplodocus

Scenes reconstructed from the available fossil evidence.

Diplodocus in its habitat, photo 1

1 of 7

Lived alongside

Found in the same rock formations

A rock formation can hold fossils laid down millions of years apart, so not every animal here met Diplodocus.

The evidence

The science behind Diplodocus

Which parts of the picture come from its own bones, and which come from its relatives.

From its own fossils

  • Skeletons show a long neck, a low trunk and a tail that narrows into a whip-like tip.
  • The small skull carries slender teeth at the front of the jaws.
  • Forked bones beneath the tail form the double beams that gave Diplodocus its name.

Borrowed from relatives

  • Very little of the skeleton needs borrowing: almost the whole body is known from its own bones.
  • Missing bones in individual skeletons can be compared with Barosaurus and Apatosaurus.

Still unknown

  • The species identity and complete body proportions of the youngest skulls.
  • The size and extent of any small spines along its back.
  • Its color and usual neck position.

Often drawn wrong

  • Its tail was held above the ground, rather than dragged behind it.
  • Its front feet were compact columns, rather than elephant feet with a row of nails.
  • Tall spikes along its back have no fossil support.

Discovery timeline

  1. 1878Named itMarsh
  2. 1999PostureStevens & Parrish
  3. 2012How it fedYoung et al.
  4. 2015Family treeTschopp, Mateus & Benson
  5. 2018Growing upWoodruff et al.

Key papers

The research behind what we know of Diplodocus

Close relatives

Other members of Diplodocidae

Sources: Wikidata