The neck and head of Barosaurus. Royal Ontario Museum


Barosaurus (Greek for "heavy lizard"); pronounced BAH-roe-SORE-us


Plains of North America

Historical Period:

Late Jurassic (155-145 million years ago)

Size and Weight:

About 80 feet long and 20 tons



Distinguishing Characteristics:

Extremely long neck and tail; tiny head; relatively slender build

About Barosaurus

A close relative of Diplodocus, Barosaurus is virtually indistinguishable from its harder-to-pronounce cousin, save for its 30-foot-long neck (one of the longest of any dinosaur, with the exception of the eastern Asian Mamenchisaurus). Like the other sauropods of the late Jurassic period, Barosaurus wasn't the brainiest dinosaur that ever lived--its head was unusually small for its massive body, and easily detached from its skeleton after death--and it probably spent its entire life foraging the tops of trees, protected from predators by its sheer bulk.

The sheer length of Barosaurus' neck raises some interesting questions. If this sauropod reared up to its full height, it would have been as tall as a five-story building--which would have placed enormous demands on its heart and overall physiology. Evolutionary biologists have calculated that the ticker of a such a long-necked dinosaur would have had to weigh a whopping 1.5 tons, which has prompted speculation about alternate body plans (say, additional, "subsidiary" hearts lining Barosaurus' neck, or a posture in which Barosaurus held its neck parallel to the ground, like the hose of a vacuum cleaner).

One interesting, and little-known, fact about Barosaurus is that two women were involved in its discovery, at a time when American paleontology was in the grips of the testosterone-fueled Bone Wars. The type specimen of this sauropod was discovered by the postmistress of Pottsville, South Dakota, Ms. E.R. Ellerman (who subsequently alerted the Yale paleontologist Othniel C. Marsh), and a South Dakota landowner, Rachel Hatch, guarded the remainder of the skeleton until it was eventually excavated, years later, by one of Marsh's assistants.

One of the most famous reconstructions of Barosaurus resides in the American Museum of Natural History in New York, where an adult Barosaurus rears up on its hind legs to defend its young from an approaching Allosaurus (one of this sauropod's natural antagonists during the late Jurassic period). The trouble is, this posture would almost certainly have been impossible for the 20-ton Barosaurus; the dinosaur would probably have toppled over backward, broken its neck, and nourished that Allosaurus and its packmates for an entire month!

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Your Citation
Strauss, Bob. "Barosaurus." ThoughtCo, Aug. 25, 2020, Strauss, Bob. (2020, August 25). Barosaurus. Retrieved from Strauss, Bob. "Barosaurus." ThoughtCo. (accessed May 31, 2023).