BRONTOSAURUS
Possibly the most commonly recognized dinosaur, the physical appearance of Brontosaurus excelsus (brawn-toe-sore-us ex-cell-sus) has changed dramatically in the 138 years since its discovery.
Original Discovery
Brontosaurus was first discovered in 1879 by the famous paleontologist Othniel Charles Marsh during the famous "Bone Wars". Two year prior, Marsh had discovered a similar animal he called Apatosaurus (a-pat-O-sore-us). In 1903, it was decided that the two animals were too similar to represent two distinct species and were united under the name Apatosaurus. Recently, in 2015, a new study of the original Brontosaurus bones was released. This new study indicated that Brontosaurus was deserving of its own genus and was reinstated as a real dinosaur.
The general public is more familiar with the image of Brontosaurus shown above than with the real appearance of the animal. This artistic rendering shows a tail dragging, box headed Brontosaurus living in a swamp, with most individuals being partially submerged. These Brontosaurus can be brought to the 21st century view by changing a few key details. There is no evidence in fossilized track ways of dinosaurs dragging their tails on the ground and for most species, dragging the tail was physically impossible without breaking several bones. The somewhat famous box head of Brontosaurus is now known to be inaccurate. This head shape was based on partial skull material from an entirely different animal. By comparing Brontosaurus to its closest relatives, Apatosaurus and Diplodocus (di-plod-dough-cuss), the head of Brontosaurus has changed from short and boxy, to long and flat. And finally, it is now known that the long necked sauropod (sore-oh-pod) dinosaurs were very terrestrial and did not require water to support their massive bodies. Taking this information into account, the real Brontosaurus would have looked like the animal below. Sadly, the animal below is not the animal we see in popular culture depictions of Brontosaurus. Instead, the highly outdated view of Brontosaurus persists.
Physical Appearance
Ecology
Brontosaurus lived during the late Jurassic, 155-151 million years ago, in the Morrison Formation, an area that stretches from Canada in the north to New Mexico in the south and from Utah in the west to Nebraska in the east. Brontosaurus lived alongside many famous dinosaurs, including Stegosaurus (steg-oh-sore-us) and Allosaurus (al-low-sore-us). Brontosaurus could grow to be 72 feet long and comfortably hold its head 20 feet above the ground. As large as it was, Brontosaurus was small compared to some of its neighbors. Brachiosaurus (b-rack-E-oh-sore-us) held its head 54 feet above the ground, and Seismosaurus (size-moe-sore-us) could grow to be 131 feet long!
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Healthy, full grown Brontosaurus would have little to no natural predators. Young and sick individuals would have been vulnerable to carnivores such as Torvosaurus (tore-voe-sore-us) and Allosaurus. Brontosaurus would have avoided competition from other sauropods by being able to browse vegetation at both low and high vantage points.
Extinction
For some unknown reason, at the end of the Jurassic nearly all of the sauropods in the same family as Brontosaurus went extinct. It is possible that they were out competed by the descendants of animals like Brachiosaurus. These descendants called titanosaurs (tie-tan-oh-sores) took the best parts of the two sauropod groups and used them to their advantage. Whatever the reason, Brontosaurus went extinct millions of years before Tyrannosaurus and Triceratops evolved and the three animals never met, despite what movies might depict.
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Image Credits
All images have been cropped to fit the space required
All images are used under Fair Use laws
Image credits are listed from top to bottom and from left to right
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Brontosaurus
Original artwork by: Davide Bonadonna
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Brontosaurus parvus
Original picture by: Rob DiCaterino
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Brontosaurus
Original painting by: Charles R. Knight
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The Other Dinosaurs of the Morrison Formation
Original artwork belongs to: Shadow Raven Studios
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Dead Apatosaurus
Original film belongs to: Universal Studios
