April 4, 2022 Scott Kraus

Barosaurus is Not a Commonly Recognized Dinosaur

The Barosaurus was an herbivorous dinosaur that lived during the Upper Jurassic period, around one hundred and fifty million years ago! Its name is derived from the Greek words ‘barys’ and ‘saurus’, which literally translate as ‘heavy lizard.’ Barosaurus was a long necked dinosaur, and a fairly close relative of the much better known Diplodocus. The Barosaurus may not be as well-known as its cousin, however, or as well represented in museum collections, but it’s still a fascinating creature.

Quick Facts

What Family Did Barosaurus Belong To?

Like modern animals, scientists who study dinosaurs have categorized the species they have uncovered so far into different ‘families’ or subspecies. Barosaurus belongs to the family Diplodocidae, which is comprised of other species of dinosaur that it shares traits with.

What Did Barosaurus Look Like?

Barosaurus shared many physical traits with other long necked plant eaters, although its neck was a little longer than most, and it’s tail a little shorter.

This was one of the bigger herbivores too, with some of the larger specimens discovered so far believed to have weighed twenty metric tons – that’s about the same as twenty small compact cars! From the top of its head to the end of its tail, Barosaurus measured about twenty five meters, or seventy five feet.

To give you some idea of just how tall Barosaurus was, an adult who raised itself up on its hind legs would have been able to look into the fifth story of a typical city building.

So far, with no Barosaurus skulls having been discovered, there’s no concrete evidence as to what its face or head would have looked like, but scientists believe that it probably had the same characteristically small head with blunt, flat teeth for grinding tough, woody plant material.

Barosaurus Looooong Neck

When you imagine how tall the Barosaurus was, it’s easy to imagine just how long its neck must have been.

What’s interesting is that even though its neck was so long, it only had fifteen or sixteen vertebrae in its neck – and humans have seven in our short necks. That probably explains why some of the Barosaurus vertebrae that have been discovered are more than one meter or thirty nine inches long!

Barosaurus Big Heart

There’s been a lot of speculation about just how the Barosaurus managed to pump blood all the way from its heart to its head, with that incredibly long neck in between them.

Of course, soft tissues like organs are not preserved when dinosaur fossils are formed, so there’s no hard evidence, but there’s been a lot of speculation.

One theory is that the Barosaurus had a heart that weighed approximately one and a half tons – the size that would have been necessary to generate enough blood pressure to keep the animal’s brain supplied with oxygen. Another (much more outlandish) theory is that Barosaurus might have had more than one heart to do all that pumping.

A more realistic idea is that the Barosaurus may have had a system of valves in it’s neck, that allowed the blood to flow incrementally upwards – much like a lock system in a canal, and like the valves we know exist in giraffe’s necks.

Whatever the truth about Barosaurus was, however, the fact is that this was one dinosaur that really DID have a lot of heart!

Where Did Barosaurus Live?

The first Barosaurus remains were found in South Dakota, and later specimens were uncovered in Utah. This hints that Barosaurus’s prehistoric range may have included large parts of North America.

For a while, scientists believed that they had also found Barosaurus remains in Tanzania, but those fossils were found to come from a different, albeit it probably related, species of long necked herbivore.

Based on their diet, which was based purely on vegetation, and mainly on vegetation from the tops of trees, it’s safe to say that when Barosaurus roamed the American West, it was mostly covered with prehistoric forest.

What Did Barosaurus Eat?

Like all of the other long necked dinosaurs discovered to date – and modern day giraffes – the Barosaurus was perfectly designed to eat leaves from the top of prehistoric trees. That’s exactly what they did eat too.

Barosaurus, like all their other long necked cousins, were completely herbivorous, in spite of their huge size. They lived on a diet comprised entirely of leaves and other plant material – but just imagine how many tons of leaves they must have consumed at each sitting!

How Did Barosaurus Move?

As you can imagine, with a mass of more than twenty tons, Barosaurus wasn’t the speediest of dinosaurs! It was built for size and height, rather than for speed and agility (which suited it, and other herbivores perfectly.) Given that weight, and the less than aerodynamic design of their bodies, it’s almost certain that the Barosaurus had a ponderous, heavy gait.

There is some evidence, however, that suggests that while Barosaurus wouldn’t have won any running races with some of its compatriots from the same time period; it could raise itself up on its back legs.

The evidence suggests that the Barosaurus would use its powerful back legs to push its weight off the ground, raising its front feet off the ground – probably in self-defense, or to reach just a little bit higher than that immensely long neck could already reach!

How Did Barosaurus Protect Itself?

As with all other herbivores of the time, Barosaurus did have a few predators that weren’t averse to hunting it, and it did need to defend itself. Smaller predators probably would not have risked attacking a fully grown Barosaurus, but there were larger carnivores in the area at the time that probably would have seen Barosaurus as a very nice sized meal.

Its enormous bulk served as a deterrent to some predators, but as we’ve already mentioned, on occasion, Barosaurus would have to raise itself onto its back feet, and use its front feet as a further deterrent.

Like its cousins, the Diplodocus, Barosaurus also used its long, heavy tail as a ‘club’ swinging it with a force that could crack bone when it connected with a hapless predator.

Where and When Was Barosaurus Discovered?

The very first Barosaurus was discovered in 1889 by a Ms. Kellerman, and excavated by Othniel Marsh and John Hatcher – however, that first specimen was far from complete, and only six tail vertebrae were excavated by Messer’s Marsh and Hatcher.

In 1929, a much more complete specimen was discovered by Earl Douglass at the Carnegie Quarry, and several more partial specimens have been unearthed since then in various parts of the US. The fact that no complete specimens have been found as yet is actually not that surprising – in fact, it’s the same case with many herbivores from the period – either they were a carnivore’s prey before they died, or they may have been a meal for a scavenger after they died of natural causes, which often explains the lack of complete skeletons from herbivorous dinosaurs.

So far, the only examples of Barosaurus have been found in what is known as the Morris Formation – a layer of late Jurassic sedimentary rock that’s spread across the western US from the Rocky Mountains to the Great Plains.

It’s interesting to note the connection between the discovery of Barosaurus specimens and US millionaire Andrew Carnegie. The well-known steel magnate was the financier of Douglass’s early excavations, and the quarry where his 1929 specimen was found was named after the wealthy industrialist.

The discovery of Barosaurus was, in fact, a part of the period of US paleontological history known as ‘the Bone Wars’ – a period during the late 19^th century, when archaeologist and amateur enthusiast alike were digging up the American west looking for dinosaur bones.

How Do We Know When the Barosaurus Lived?

As with most dinosaur fossil discoveries, scientists have used a variety of methods to pinpoint the period during which Barosaurus walked the earth.

The methods that have been used to establish the time period when Barosaurus lived include radiometric testing, biostratigraphy (or dating of the rock in which the fossils are found) and paleomagnetic methods, which involve recording the magnetic field in the rock.

All of these testing methods have confirmed the period during which Barosaurus fossils would have been deposited in the rock they have been found in, which confirms the age range of the species.

What’s Strange About Barosaurus?

There isn’t much about Barosaurus itself that’s particularly weird – unless you count the fact that it’s believed to have had only nine dorsal vertebrae – compared to other dinos in this subspecies, who all had ten.

What is slightly weird about Barosaurus is that so far, no one has found a specimen that includes a head or skull bone, so there’s still a fair amount of speculation as to what Barosaurus actually looked like!

Where Can You See Barosaurus?

There are several specimens of the Barosaurus in various museums today, most notably the American Museum of Natural History in New York, and the Royal Ontario Museum in Toronto. Most of the exhibits are made up of skeletal fragments from various sites, and until a complete Barosaurus is found somewhere, we’ll only really be able to see complete representations of this huge beast in its entirety in books and artistic renditions.