Torvosaurus tanneri

Artwork depicting a Torvosaurus dinosaur
Torvosaurus tanneri

NPS / Bob Walters and Tess Kissinger

Torvosaurus tanneri is a species of theropod dinosaur from North America. It has been found in the Morrison Formation, a layer of sedimentary rock that dates to the Late Jurassic Period, about 150 million years ago. Torvosaurus was the largest predator found in the Carnegie Quarry and was one of the largest predators in the Morrison Ecosystem. Fossils of Torvosaurus were uncovered from Dinosaur National Monument during excavations in the early 1900s. Unfortunately, there are no bones of Torvosaurus left on the Wall of Bones in the Quarry Exhibit Hall today.

A Large (and Rare) Predator

Torvosaurus tanneri was just one of several kinds of large predatory dinosaurs roaming Late Jurassic North America. However, despite its size, its remains are much more rare to find than those of other predators in the Morrison Ecosystem. Scientists aren't exactly sure why this is the case, but it's possible that the Morrison Ecosystem just couldn't support as many Torvosauruses as it could other, smaller predators. Other predatory theropods of the Morrison Ecosystem included Allosaurus and Ceratosaurus. While all three of these dinosaurs lived at in the same time in the same habitat, Allosaurus and Ceratosaurus were both smaller and less beefy than Torvo. They also seem to have been more abundant, with Allosaurus being easily one of the the most common and well-known large predators of the Late Jurassic. Both Allosaurus and Ceratosaurus were scientifically described in the late 1800s, during a period of intense paleontological competition and discovery known as "the Bone Wars." Meanwhile, Torvosaurus was found and described much later in 1979. This is probably due to its remains being much scarcer than those of other large Late Jurassic predators.
A photo of the Torvosaurus tanneri vertebra fossil. It sits on a black background beside a ruler for scale.
This vertebra from Torvosaurus tanneri was uncovered at Dinosaur National Monument during excavations that took place in the early 1900s. It's the only fossil from Torvosaurus tanneri ever found at the monument.

Photo by John Foster

Where Are the Torvosaurus Fossils?

Today, no bones of Torvosaurus tanneri are visible on the Wall of Bones at the Quarry Exhibit Hall. Its remains were initially found at Dinosaur National Monument during excavations of the historic Carnegie Quarry in the early 1900s. While there is one record of a humerus (upper arm bone) having been found, no specimen number was ever given for it and it hasn't been located in any museum collections yet. However, according to Dinosaur National Monument paleontologist, ReBecca Hunt-Foster, there is a record of a single Torvosaurus vertebra having been found during the Carnegie Quarry excavations. That vertebra was extracted and shipped to the Carnegie Museum of Pittsburgh. However, the Carnegie Museum has since traded that Torvosaurus vertebra to the Denver Museum of Nature and Science in Colorado. As of 2024, the original Torvosaurus tanneri vertebra found at Dinosaur National Monument is still with the Denver Museum.

Last updated: April 26, 2024

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