A chance discovery in Mississippi provides the first evidence of an animal closely related to Triceratops in eastern North America. The fossil, a tooth from rocks between 68 and 66 million years old, shows that two halves of the continent previously thought to be separated by seaway were probably connected before the end of the Age of Dinosaurs.

<span style="font-family:"font-size:18px;">"The shape of this tooth, with its distinctive split root, is absolutely unique among dinosaurs," Farke continued. "We only have the one fossil, but it's more than enough to show that an animal very similar to Triceratops-perhaps even Triceratops itself-made it into eastern North America."

Due to a lack of preserved rock and fossils, scientists weren't sure precisely when the seaway disappeared and animals could once again walk freely across North America. The newly described fossil strongly suggests that this happened when large dinosaurs such as Tyrannosaurus and Triceratops were still around, before the major global extinction 66 million years ago.

Phillips described the moment of discovery: "I was excited because I knew it was a dinosaur tooth, and dinosaur fossils are rare discoveries east of the Mississippi River. I called my volunteer, Michael Estes, over to share in the discovery, and he was beside me in seconds. I knew it wasn't a duck-billed dinosaur, and within 30 minutes of having found it, I posted on Facebook that I'd collected some rare plant-eating dinosaur tooth. It was none other than my colleague Lynn Harrell who made the suggestion, within minutes of my post, that it looked like a ceratopsian tooth."

"The discovery is shocking because fossils of ceratopsid horned dinosaurs had never been discovered previously from eastern North America. It's certainly the most unique and important vertebrate fossil discovery I've ever made," said Phillips.

The fossil is housed at the Mississippi Museum of Natural Sciences.

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