Fossil Friday – Tyrannosaurus tooth

The vast majority of the Western Science Center’s fossil collection comes from Pleistocene deposits in Riverside County, so most of our specimens are less than 200,000 years old. Being so geologically young, birds are almost the only dinosaurs in our collection, as birds were the only dinosaurs to survive the mass extinction at the end of the Cretaceous Period 65 million years ago. We do, however, have a handful of much older, non-avian dinosaurs at the museum.

On the left above is a partial single tooth from Tyrannosaurus rex from the Late Cretaceous Hell Creek Formation in Montana, which was collected by Harley Garbani and donated to the museum by Harley and his wife Mary. The tooth was apparently found isolated, which is not uncommon with dinosaurs as they shed teeth throughout their lives. As is typical of Tyrannosaurus and other theropods, the tooth has serrated cutting edges, one of which is visible near the left edge of the tooth. There is noticeable apical wear at the tip of the tooth, which is somewhat rounded off.

This tooth was one of the first subjects for our molding and casting program. At the center of the photo is an unpainted resin cast of the tooth, and on the right is a painted cast. The serrated cutting edge is actually more visible in the cast than in the original specimen.

The original specimen is on display at the Western Science Center as part of the “Harley Garbani: Dinosaur Hunter” exhibit. Replicas of the tooth will be available in the museum store early next year.


2 responses to “Fossil Friday – Tyrannosaurus tooth

  1. you know those teeth look more for crushing then slicing and dicing, they are too thick to be knives. more like hammers. I would say t rex was a scavenger like hyenas. eat it after it is dead from old age or injury maybe?


  2. About 25 years ago Jack Horner suggested that Tyrannosaurus might have been purely a scavenger, but I think this is no longer widely accepted (although almost all predators engage in scavenging given the opportunity). Almost everything about Tyrannosaurus anatomy suggests some type of active predation. Moreover, conical teeth are actually pretty widespread among predators, including crocodiles and alligators, the canines of dogs and most cats (sabertooths are an exception), killer whales and other dolphins, seals and sea lions, bears, wolverines,…the list goes on. Conical teeth are really good for punching holes in prey and then holding on to it, so a knife is probably not a good analogy. Cats have conical front teeth for catching and killing prey, and blade-like back teeth for slicing it up. Crocodiles have conical teeth for capture, but mostly lack the blade-like slicing teeth; instead, they get a tight grip and rip their prey apart. So I don’t think a thick-section tooth precludes active predation in Tyrannosaurus.


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