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Discovery of T. Rex - The first fossil Tyrannosaur Dinosaur

Like most things in science, Tyrannosaurus rex's discovery is not straight forward; it was actually discovered and independently named 3 different times!

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1. The first time T. rex was discovered... But it doesn't count!

The discovery of T. rex begins during the Bone Wars of the late 1800's. In 1892, during the heat of the bone wars between Edward Cope's and Othniel Marsh's fossil hunting armies, Cope discovered two partial vertebra. He haphazardly studied them and made the assumption they came from a new ceratopsid dinosaur. He named it "Manospondylus gigas", which means "Giant Porous Vertebra." Cope then continued his frantic and reckless pursuit of dinosaur specimens and this new beast was all but forgotten for over 100 years.

Onward to over 100 years later... In 2000, Peter Larson from the Black Hills Institute found the spot where the original Manospondylus gigas was discovered. They excavated and found more of the original animal. Larson realized the animal Cope described over one hundred years ago is a T. rex!

Since "Manospondylus gigas" is the actual first T. rex discovered, the name T. rex would normally be deemed invalid and all T. rex's would become M. gigas. However, the International Code of Zoological Nomenclature (ICZN), which has the rules to naming animals, did an update in 2000. Any name that has been published enough and has been considered valid for 50 years can't be replaced by an older name. Since, T. rex fits these rules, the "tyrant lizard king" dinosaur will not be renamed.

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2. The second time T rex was discovered. This is the one that counts!

After the bone wars of the late 1800's was winding down, fossil hunters continued quenching the public's thirst for dinosaurs. Museums were still looking for trophy specimens to mount. Fossil hunters like Barnum Brown and Charles Sternberg rushed to collect specimens for major museums. In 1902 Barnum Brown, working for the American Museum of Natural History (AMNH), was led to some bones eroding out of the earth by a local land owner. These bones turned out to be something not seen before near Hell Creek in Montana. It was a large theropod with a huge skull and giant teeth. It took a full 3 years to excavate the beast. In 1905 when it was fully excavated (all 10% of it), Barnum transported the specimen to Osborn, the paleontology curator at the AMNH. There, Osborn studied and described it. He named it Tyrannosaurus rex (Tyrant Lizard King). It is specimen AMNH 973, and is now the holotype specimen for T. rex.

The reconstructed holotype was displayed at AMNH for a few years, until larger and more complete ones were found. It eventually got packed away and placed into storage. In 1941, when the United States entered WWII, the holotype T. rex was sold to the Carnegie Museum in Pittsburgh to protect it from being bombed by the Germans in New York (which was a real possibility). The holotype was then renamed CM 9380. This reconstructed specimen is still on display at the Carnegie Museum of natural history. They have no plans to ever move it. This fine holotype is pictured at the bottom of this article.

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3. The other other first time T. rex was discovered. This one really should have been the real first one that counts... if it wasn't for a page number!?!?

Barnum actually discovered another T. rex two years before his discovery of the holotype specimen. However, due to not sending it to AMNH in a timely manner, and a small mistake by Osborn, it ended up not being the first official T. rex.

In 1900, Barnum was doing excavations in Wyoming, looking for a trophy Triceratops skull for the AMNH. There, he discovered a large carnivorous theropod, that was around 13% complete. Instead of shipping this intriguing fossil back to New York, Barnum continued looking for a trophy Triceratops skull. When he finally shipped it back the AMNH, Osborn saved it for a paper on "Tyrannosaurus and Other Cretaceous Carnivorous Dinosaurs" that would be published in 1905. In this paper, the 1902 specimen was also described. Unfortunately, Osborn thought the specimen found in 1900, labeled AMNH 5866, was from a different carnivorous dinosaur. He named this dinosaur Dynamosaurus imperiosus the "Imperial Powerful Lizard". The main reason for thinking it was a different animal was there were ankylosaur armor plates found with the specimen. He thought this specimen was covered in armor plates. In fact, the armor plates found with the specimen were probably the stomach contents of this tyrannosaur.

Later, after the paper was published, Osborn realized Tyrannosaurus was actually the same animal Dynamosaurus. As nomenclature rules go, the name of the specimen in the first publication is used. However, since both specimens were published in the same paper, the page numbers were used to determine the correct name of this type of animal. The 1900 specimen was described a pages after the 1902 specimen. Thus, even though Dynamosaurus was found first, Tyrannosaurus became the official name. Dynamosaurus is now lost to the annals of history, and Tyrannosaurus is a house hold name... all due to a page number.

Conclusion

Thus ends the story of the first T. rex, or the first 3 T. rex's.
Luckily, T. rex has its nice, easy sounding name... If it wasn't for Cope rushing and not further excavating the "Manospondylus" dig site, or no one noticing a forgotten bone for over 100 years, or Barnum not sending the "Dynamosaurus" specimen back to New York in a timely manner, or because "Dynamosaurus" just happened to be placed a few pages after "Tyrannosaurus" in a publication, we are left with the name "T. rex"... the name that almost wasn't!

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Recommended T. rex Dinosaur Books and Educational Items:

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Rothschild, B. M. & Molnar, R. E. (2008) Looking again at the forelimb of Tyrannosaurus rex. In: Tyrannosaurus rex, the tyrant king. Larson, P. & Carpenter, K. (eds.). Indiana University Press. Bloomington, IN. pp.287-304.

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