This 17-million-year-old giraffe cousin had a neck built for combat

"We called it the 'strange beast' because we didn't know what it was."
Grant Currin
An illustration of the proposed head-butting behavior by D. xiezhi. Wang et al

In 1996, paleontologist Jin Meng came across something remarkable while digging through 17-million-year-old rock in western China. He found the fossilized fragment of a skull that was covered in a thick, hard layer of keratin, the protein found in human fingernails. It also sported an incredibly stout neck.

"We called it the 'strange beast' because we didn't know what it was," Meng tells IE. "It looked so odd." Now, more than a quarter-century later, Meng and a team of colleagues have finally figured out what the strange beast was — and why its head was protected by a helmet-like structure.

In the decades since the initial discovery, researchers have collected fossils from more than 50 different species of mammals that died near the location where Meng made the initial discovery. Careful analysis of those remains has finally revealed the Strange Beast's identity. The creature was a long-lost cousin of the modern giraffes. But instead of a long neck, this extinct giraffoid sported a short, thick neck and protective headgear that was perfectly suited to head-butting. 

Meng, who is now curator-in-charge of mammal fossils at the American Museum of Natural History, and several co-authors describe the find in an article published Thursday in the peer-reviewed journal Science. 

Tiny clues helped researchers make the connection

At first glance, the new species looks nothing like a modern giraffe. But Meng says he and his collaborators found "several lines of evidence showing that this is a species related to a giraffe." Some of the best evidence came from the teeth.  The new species' "dental morphology is similar to that of what we see in living giraffes," he says.

That isn't all. New methods made it possible for researchers to look inside some of the fossils to identify subtle similarities that just weren't accessible to researchers in the 1990s when the first fossils were discovered. "Thanks to advances in technology, we can now do a CT scan of this creature," Meng says. Those scans allowed researchers to "see the shape and the structure of the cochlear and semicircular canal," deep in the ear. "Those structures turned out to be similar to the leaving giraffe," he says.

The neck is impressive in its own way

The new species doesn't have a long neck like modern giraffes, but that doesn't mean it's boring. 

"The neck is incredible," Meng says. Researchers have never seen anything quite like it. For most mammals, the main job of the vertebra that attaches to the skull, which is called the atlas, is to support the head. For a few species, the atlas and the vertebrae beneath it play another very important role. For males that compete for females in head-butting competitions, having strong upper vertebrae is crucial in allowing an individual to reproduce and pass his genes to the next generation

The newly identified species' neck is better suited to this kind of competition than any species alive today. For one thing, the atlas and the other neck bones are massive. They are significantly bigger, thicker, and wider than bones in any other species of similar body size. Their shape is also suggestive of some serious head-butting. Under normal circumstances, the neck vertebrae are attached to each other and to the head similar to most other mammals. But when the animal put its head down — before it rammed into another male — the surfaces of the bones lined up perfectly, creating a single battering ram that probably made it possible for the animal to deliver an enormous amount of force without injuring itself. 

The researchers suggest that this neck is better suited to head-butting competition than anything researchers have seen. "It's very robust, very precise, and very incredible," Weng says. Combined with the keratin helmet, this ancient species may have been the most powerful head-butting mammal (for its size) ever to walk the earth. 

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