Last April, in my final post for National Geographic, I wrote about a new, as-yet-unnamed horned dinosaur found in Mexico. I thought it was the perfect foil for a send-off, highlighting how we truly are in the golden age of dinosaur discovery. Now, less than a year after that paper by Hector Rivera-Sylva and coauthors was published, that dinosaur has a name.

The horned dinosaur has been dubbed Yehuecauhceratops mudei. It's one of several mysterious species uncovered across northern Mexico in the last decade, and its timing really couldn't be better. Yehuecauhceratops, Rivera-Sylva and colleagues write, is a close relative of Nasutoceratops from Utah - itself only named in 2013 - and joins a growing family of these long-horned, deep-snouted dinosaurs that stretched from Alberta to Coahuila.

More and more, it seems that western North America saw an explosion of horned dinosaur species during the Late Cretaceous. This fits a broader pattern of dinosaur evolution at the time. If you were to survey the dinosaur fauna spread from Alaska to Mexico between 80 and 70 million years ago, you'd see a changing roster of horned dinosaurs, tyrannosaurs, hadrosaurs, ankylosaurs, and more in their own little geographic pockets. It'd be perfect for filling out your dinosaurian life list. But the question is why.

Isolation is key to this kind of evolutionary divergence. Something was separating populations of dinosaurs, allowing them to evolve into dramatically different forms in various places throughout western North America. Perhaps there were geographic barriers, as stark as an impassible floodplain, or maybe the particular diets of dinosaurs kept them pinned to limited ranges. No one knows yet. But every new species helps outline this grand evolutionary pattern, and Mexico is increasingly adding to the record. As Rivera-Sylva and coauthors sign off their paper, "Although the ceratopsian material known from Northern Mexico is currently rare and mostly fragmented, there is an evident potential to discover more and better preserved specimens in the near future." There are more horned faces we have yet to meet.

Dinosaur map
A map of Mexican ceratopsids. Credit: Rivera-Sylva et al. 2017

Fossil Facts

Name: Yehuecauhceratops mudei

Meaning: Yehuecauhceratops is a combination of the Nahuatl word for ancient and the Greek word for horned face, while mudei honors the Museo del Desierto in Coahuila, Mexico.

Age: Cretaceous, around 74 million years ago.

Where in the world?: La Salada, Mexico.

What sort of critter?: A horned dinosaur related to Nasutoceratops.

Size: About 10 feet long.

How much of the organism’s body is known?: A partial skull, left scapula, left femur, parts of the hips, a vertebra, ribs, and fragments.


Rivera-Sylva, H., Frey, E., Stinnesbeck, W., Guzmán-Gutiérrez, J., González-González, A. 2017. Mexican ceratopsids: Considerations on their diversity and biogeography. Journal of South American Earth Sciences. doi: 10.1016/j.jsames.2017.01.008

Previous Paleo Profiles:

The Light-Footed Lizard
The Maoming Cat
Knight’s Egyptian Bat
The La Luna Snake
The Rio do Rasto Tooth
Bob Weir's Otter
Egypt's Canine Beast
The Vastan Mine Tapir
Pangu's Wing
The Dawn Megamouth
The Genga Lizard
The Micro Lion
The Mystery Titanosaur
The Echo Hunter
The Lo Hueco Titan
The Three-Branched Cicada
The Monster of Minden
The Pig-Footed Bandicoot
Hayden's Rattlesnake Demon
The Evasive Ostrich Seer
The Paradoxical Mega Shark
The Tiny Beardogs
The Armored Fish King
North America's Pangolin
The Invisible-Tusked Elephant
The Mud Dragon
The Spike-Toothed Salmon
The Dream Coast Crocodile
Buriol's Robber
Ozimek's Flyer
The Northern Naustoceratopsian
The High Arctic Flyer
The Tomatillo From the End of the World
The Short-Faced Hyena
The Mighty Traveler from Egg Mountain
Keilhau's Ichthyosaur