An Ultimate Guide to Diplodocus: The Double Beam Lizard

Leave a comment / / Updated on: 22nd October 2023

Name Meaning“Double beam”Height4.5 meters (14.7 feet)
PronunciationDee-ploh-doe-kusLength24-30 meters (78.7-98.4 feet)
EraMesozoicLate JurassicWeight12-23 metric tons (13.2-25.3 short tons)
ClassificationDinosauria, Saurischia & SauropodaLocationUSA (North America)

Diplodocus Pictures

The Diplodocus / warpaintcobra via Istock

The Diplodocus

Gage Beasley Prehistoric's Diplodocus Concept
Gage Beasley Prehistoric’s Diplodocus Concept

The term Diplodocus comes from the Greek words diplos and dokos, which translate to double and beam, respectively.

These words refer to the chevron bones in this dinosaur’s tail underside, making it quite unique at the time.

The Diplodocus giant inhabited our planet 154-152 million years ago and was widely distributed across North America.

This dinosaur was a herbivorous sauropod with a long neck and an even longer tail.

The legs were sturdy, while the skull was unusually small, considering its overall size.

Before discussing more details, it is important to mention the three recognized species in the genus: D. longus, D. carnegii, and D. hallorum.

Gage Beasley's Prehistoric Shirt Collection
Gage Beasley’s Prehistoric Shirt Collection

Physical Characteristics

The Diplodocus was a dinosaur in the Jurassic Period and lived in North America. | CoreyFord via Getty Images

The Diplodocus had a typical sauropod appearance.

Here are some of the key features of Diplodocus you need to know:

  • It had a very long neck consisting of at least 15 vertebrae. This neck supported a relatively small skull, and it was likely held horizontally and was not flexible enough to be elevated. 
  • It had peg-like teeth arranged only in the anterior parts of its jaws. The teeth pointed forward.
  • Its hindlimbs were longer than the forelimbs.
  • It had an unusually large claw on one digit of each forelimb.
  • Skin impressions revealed that the Diplodocus had keratinous spines similar to those of iguanas. These spines were narrow and pointed, arranged on its tail and possibly on the neck and back. They reached approximately 18 centimeters (7.1 inches) in length.
  • Fossilized skin revealed that the Diplodocus also had scales across its body, which were of various shapes – polygonal, pebble, ovoid, rectangular, dome, and globular. The shape of the scales possibly indicated their location on the body, and they measured between 1 and 10 millimeters.
  • The whip-like tail was extremely long and consisted of approximately 80 caudal vertebrae. It likely served to counterbalance the long neck.

The truly interesting part when discussing the Diplodocus is its size.

A specimen belonging to Diplodocus carnegii is now considered among the world’s longest, most complete dinosaur skeletons.

It measures 24-26 meters (78.7-85.3 feet) long and weighs approximately 12-14.8 metric tons (13.2-16.3 short tons). Can you imagine what a giant it was?!

Gage Beasley Prehistoric's Diplodocus Size Comparison Chart
Gage Beasley Prehistoric’s Diplodocus Size Comparison Chart

Another species in the genus, Diplodocus hallorum, is believed to have been even longer, except its fossils didn’t reveal such a complete skeleton.

This species is thought to have had the size and weight of approximately four elephants!

In 1991, scientists provided an estimated length of 33 meters (108.3 feet), although it was later argued that this number wasn’t truthful.

Instead, D. hallorum might have reached an average length of 39-45 meters (128-147.6 feet) and a maximum length of 52 meters (170.6 feet).

A long Diplodocus | Elenarts108 via Getty Images

Consequently, the weight was estimated at 80-100 metric tons (88-110 short tons).

These numbers weren’t set in stone, as they were subsequently debated and scaled down to 35 meters (114.8 feet).

Then, scientists suggested a size of 29 meters (95.2 feet) and a weight of 23 metric tons (25.3 short tons).

In short, whether it measured 24 or 50 meters, the Diplodocus was a giant nonetheless!

Habitat and Distribution

Diplodocus fossils were unearthed in the following locations:

  • Marshall P. Felch’s quarry, Garden Park, Colorado
  • Como Bluff, Wyoming
  • Sheep Creek, Wyoming
  • Dinosaur National Monument, between Colorado and Utah
  • A canyon west of San Ysidro, New Mexico
  • Mother’s Day Quarry, Carbon County, Montana

As such, Diplodocus fossils were widely distributed across the Morrison Formation, so we’ll focus on its habitats and ecosystems.

The Morrison Formation had a relatively dry habitat with a semi-arid climate.

Some scientists compare it to a savanna but mention that it did not support the angiosperms characteristic of savannas.

Instead, the ecosystem supported the growth of conifers, which dominated the environment, cycads, tree ferns, ginkgos, and horsetail rushes.

Diplodocus | Elenarts108 via Getty Images

The environment was rich in flood plains, so the vegetation and the prehistoric creatures inhabiting it were likely riparian.

Although the Morrison Formation was a dry habitat, fossil evidence shows it served as a relatively good environment for year-round residents.

However, some creatures likely engaged in migratory behavior during extreme drought.

Many dinosaurs discovered in the Morrison Formation were distributed throughout Portugal’s Lourinha Formation.

Although no Diplodocus fossils were unearthed there, there is a possibility they roamed through prehistoric Portugal as well.

Behavior and Diet

Diplodocus from the Jurassic era | Warpaintcobra via Getty Images

The Diplodocus was likely a cathemeral creature, meaning it was irregularly active at any time of night or day.

At first, it was suggested that the Diplodocus and other sauropods like Brachiosaurus and Apatosaurus were aquatic.

Over the years, however, scientists agreed they were fully terrestrial, although they might have lived close to water sources.

One major concern for scientists was Diplodocus’ posture.

The most notable depiction of this creature comes from a 1910 reconstruction, which shows two Diplodocus dinosaurs on a river bank.

They have lizard-like, widely-splayed limbs, and one of them keeps its neck vertically.

Diplodocus leaning over to eat or drink | Warpaintcobra via Getty Images

Later depictions also portray them with their necks high up in the air, browsing on tall trees.

However, as it turns out, these famous portrayals are far from the truth.

First, sauropod footprints revealed that the legs weren’t splayed and lizard-like.

Secondly, neck studies showed that the Diplodocus likely couldn’t elevate its neck much beyond the horizontal line, and the head wasn’t raised much above the shoulder line.

Then, a 2009 study compared sauropod skeletons with those of living animals and showed that sauropod necks were much more flexible than previously thought.

However, this brings another problem to light; if Diplodocus dinosaurs did indeed raise their necks so high, how would their brains be supplied with blood?

Diplodocus Upright neck pose for D. carnegii based on Taylor et al. (2009) | Photo via Diplodocus (Marsh): its osteology, taxonomy and probable habits, with a restoration of the skeleton

Some scientists suggested that they had auxiliary hearts in their necks that pumped blood, but no evidence confirms this.

That is why it is generally accepted that a horizontal posture and limited neck flexibility are more plausible.

As for the diet of the Diplodocus, it was likely very different from the diet of other sauropods due to the form and wear patterns of its teeth.

As such, scientists propose a unilateral branch stripping feeding technique for the Diplodocus.

The Diplodocus likely fed on vegetation growing to approximately 4 meters (13 feet) tall, although this is debatable, as it depends on how flexible its neck was.

If it could raise its neck high, it might have even been able to use its tail as a stabilizer to stand on two legs, in which case it could have reached vegetation of up to 11 meters (36 feet) high.

Life Cycle

Restoration of a narrow snouted juvenile (based on the “Andrew” specimen CMC VP14128) feeding alongside broad snouted adults | Art by A. Atuchin (CC BY 4.0)

While the long neck served as a stabilizer and aid foraging, it might have also served for sexual selection and display. However, not all scientists approve of this theory.

Diplodocus dinosaurs reproduced by laying eggs, and since the females had two functional oviducts, they laid two eggs at a time.

As for their nesting habits, almost nothing is known about this aspect.

However, other sauropods have been associated with nesting sites, which revealed that they nested communally.

Females dug holes with their back feet, laid the eggs there, and then covered them in dirt and vegetation.

Two Diplodocus | estt via Getty Images

The clutches likely consisted of roughly 25 eggs each, and it is also believed that sauropods laid unusually few eggs, considering their size.

All these details may apply to the reproductive behavior of the Diplodocus and other sauropods.

Many baby dinosaurs were precocial, meaning they were quite developed right after hatching and didn’t require much adult help.

We do not know whether this was also true for Diplodocus hatchlings, but studies have shown they did indeed grow quickly and reached sexual maturity when they were approximately ten years old.

Juveniles likely also had a different snout and teeth form, which indicates their diet was different than the adult diet.

Evolution and History

Diplodocus skeletal mount at the Carnegie Museum of Natural History, Pittsburgh | ScottRobertAnselmo via Wikipedia (CC BY-SA 3.0)

The first sauropod fossil was described in 1699, although scientists weren’t sure what kind of creature it was since dinosaurs hadn’t been recognized yet.

Recent studies show that advanced sauropod lineages may have appeared much earlier than it had been previously thought – approximately 15 million years earlier.

The Diplodocus is the type genus in the Diplodocidae family, whose members are thought to have evolved in North America, although fossils were unearthed on other continents as well.

The first Diplodocus fossils were recovered in 1877, and this discovery revealed only two complete caudal vertebrae, several fragmentary ones, and a chevron.

Other discoveries followed, bringing to light more complete specimens that served as a base for detailed descriptions and analyses of the Diplodocus.

Caudal vertebrae of D. carnegii showing the double-beamed chevron bones to which the genus name refers, Natural History Museum, London | Ballista via Wikipedia (CC BY-SA 3.0)

The most notable specimens were recovered in 1899 – an adult and a juvenile – from relatively complete skeletons, which were named and described in 1901.

The latest finds occurred at a fossil site in Montana, which contained an impressive amount of juvenile fossils.

A nearly complete juvenile skull was discovered there, and it is now considered proof of age-related dietary changes.

Although only three species are recognized today, scientists named two other species over the years.

Even the type species, D. longus, is often considered a doubtful one, and several proposals to change the type species to D. carnegii were sent but rejected.

Several elements referred to Diplodocus longus, including a type caudal at the bottom, as figured in Marsh, 1896. | Internet Archive Book Images via Flickr

D. lacustris and D. hayi were once thought to belong to Diplodocus but were subsequently reassigned.

Furthermore, the fossils associated with the first species are thought to have belonged either to Apatosaurus or Camarasaurus.

The second species was moved to a genus of its own, Galeamopus.

Interactions with Other Species

Saurophaganax and D. hallorum, New Mexico Museum of Natural History and Science | Lee Ruk via Flickr (CC BY-SA 2.0)

The Morrison Formation is one of the richest sources of dinosaur fossils, so the Diplodocus likely lived in a crowded environment.

In fact, it is considered that large herbivorous sauropods like the Diplodocus dominated the territory.

While it would be quite challenging to list every single creature that lived in the Morrison Formation, we managed to create a comprehensive list that would help you envision the Diplodocus ecosystem.

Two Diplodocus dinosaurs bellow in alarm as a theropod Ceratosaurus tries to sneak up behind them | CoreyFord via Getty Images

Here are some prehistoric creatures that likely lived alongside the Diplodocus:

  • Arthropods like Tektonargus
  • Fishes
  • Amphibians like Comobatrachus and Enneabatrachus
  • Sphenodonts like Opisthias
  • Squamates like Diablophis and Paramacellodus
  • Turtles like Dinochelys and Dorsetochelys
  • Crocodyliforms like Fruitachampsa and Hoplosuchus
  • Pterosaurs like Comodactyls, Kepodactylus, and Mesadactylus
  • Various mammaliaforms
  • Numerous other sauropods, including the Haplocanthosaurus, Maraapunisaurus, Dyslocosaurus, Apatosaurus, Brontosaurus, Brachiosaurus Galeamopus, and Supersaurus
  • Ornithischians like Camptosaurus, Dryosaurus, Uteodon, Hesperosaurus, Stegosaurus and Alcovasaurus
  • Theropods like the Allosaurus, Antrodemus, Saurophaganax, Ceratosaurus, Fosterovenator, Ornitholestes, Marshosaurus, and Torvosaurus.

The Diplodocus might have faced two challenges in its habitat: coexisting with other herbivores and being preyed upon by carnivorous theropods.

The first issue was likely solved by specialized feeding techniques and adaptations, which restricted the herbivores to certain vegetation types.

The predation, however, could not have been avoided, as the Diplodocus could have fallen prey to Allosaurus, Ceratosaurus, and Torvosaurus.

Cultural Significance

Diplodocus in Jurassic World: Evolution | Photo via Jurassic World Evolution Wiki

The Diplodocus was long thought to have been the world’s longest dinosaur, which is why it is so well-studied today.

This fame brought the genus to dinosaur enthusiasts’ attention as well.

However, despite its significance in our world’s prehistoric habitats and evolutionary history, the Diplodocus isn’t as popular in the media.

Naturally, it is mentioned and described in numerous books about dinosaurs, but compared to other prehistoric creatures, few fiction books, movies, and video games used it as a character.

One of its most notable appearances is in the Jurassic World: Evolution video game, so if you want to observe a Diplodocus, check it out!


The Diplodocus is one of the most renowned prehistoric creatures.

Measuring more than 25 meters (82 feet) and weighing as much as 2-3 elephants, the Diplodocus was a giant (but not the only one!) in its habitat.

It had an unusually long neck and tail and was slightly more slender than other sauropods.

The Diplodocus lived in North America approximately 154-152 million years ago during the Late Jurassic.

Although known from multiple specimens, many aspects of its lifestyle and feeding behavior remain a mystery.

All that’s left is to hope for new scientific finds that will bring certainty to the proposed theories!


Is Diplodocus the same as Brontosaurus?

The Diplodocus and the Brontosaurus were different creatures, although both were herbivorous diplodocid sauropods.

Was Diplodocus the biggest dinosaur?

While it was once considered the longest dinosaur known, the Diplodocus is not at the very top now.

It is quite challenging to state which was the biggest dinosaur because size estimations are, after all, only estimations.

However, it is well-known that the Sauropoda clade includes the world’s largest terrestrial animals, particularly titanosaurs and diplodocids.


About The Author

Leave a Reply

Discover more from Gage Beasley Prehistoric | Recapping Timeless Creatures

Subscribe now to keep reading and get access to the full archive.

Continue reading

Scroll to Top