Science

Horned dinosaur with nasty infection reveals new species

Once upon a time, a scrappy horned dinosaur with a nasty bone infection died on the banks of a coastal river in Montana. Here's how "Judith" was found by a man out for a walk, and then recognized as a new species, with help from a Canadian museum.

Fossil found by nuclear physicist goes on display at Canadian Museum of Nature in Ottawa

An artist's rendering of Judith, a horned dinosaur Spiclypeus shipporum, shows it limping gingerly across a flood plain 76 million years ago. It had a bone infection and arthritis in its left forelimb, an examination of its fossils shows. (Mike Skrepnick)

Once upon a time, a scrappy horned dinosaur with a nasty bone infection died on the banks of a coastal river in Montana.

Seventy-six million years later, a nuclear physicist out for a walk among the steep, scrubby hills, stumbled across her fossil remains. And now "Judith" has found a new home at the Canadian Museum of Nature in Ottawa, where scientists have confirmed that it is the first of its species ever discovered.

Scientists don't know whether Judith was male or female — it was named after the Judith River rock formation where it was found by Bill Shipp, says Jordan Mallon, a paleontologist at the Museum of Nature who led the analysis of the fossil.

The first time Bill Shipp went walking on his new property looking for fossils, he spotted a cream-coloured object in the middle in this cliff. It turned out to be part of Judith's femur or thigh bone. (Joe Small)

Shipp worked as a nuclear physicist and decided to buy some land in rural Montana in 2000.

"He was looking for sort of a place to get away to do hunting and fishing," Mallon said.

Beginner's luck

Knowing there were fossils in the area, he decided to go for a walk about the property.

"Little did I know that the first time I went fossil hunting I would stumble on a new species," he recalled in a news release.

He spotted what turned out to be one of Judith's leg bones sticking out of a hill.

The man who found the fossil, Bill Shipp, wearing red shirt, and volunteers excavate the fossilized bones in 2006. Bill gave the specimen the nickname Judith, after the Judith River Formation, where the fossil was found. (Joe Small)

Over several years, he hired a paleontologist named Joe Small to help collect data about the fossil and excavate it with a team of volunteers. It was a project that ended up taking years and cost hundreds of thousands of dollars — he even had to build a road to bring in an excavator to help with the digging.

But in the end, the team managed to find half a skull, along with parts of the dinosaur's front limbs, hind limbs, hip bones and parts of its backbone — enough for paleontologists to later get a good idea of what Judith was like.

The dinosaur would have been about 4.5 to six metres long and weighed around three or four tonnes — "basically somewhere between a rhino and an elephant in size," Mallon says.

Thrilling frill

Like other horned dinosaurs, it had a massive head with a big, spiked frill and horns. But their unique configuration identify it as a new species, a missing link between earlier horned dinosaurs with outward-pointing spikes on their frill and later horned dinosaurs with forward curling spikes, the research team found.

Canadian Museum of Nature paleontologist Jordan Mallon helped identify and name the new horned dinosaur Spiclypeus shipporum. The specimen's nickname is Judith, but it is unknown whether the dinosaur was male or female. (Martin Lipman/Canadian Museum of Nature)

Mallon has given the new species the scientific name Spiclypeus shipporum. The first part of the name means "spiked shield" and the second part honours Shipp, who discovered the fossils.

Judith had a narrow, pointed beak that it would have used to munch on low-growing shrubs, leaves and twigs.

And it had four stout limbs, but it likely only walked on three — the dinosaur suffered a bone infection in its left humerus or upper arm bone, scientists discovered.

"It's just really gnarly looking, and especially toward elbow, there's this big hole that's opened up in bottom of it that would have served to drain the infection," Mallon said. "And probably it rendered that left forelimb useless for walking."

The humerus (upper arm bone) of Spiclypeus shipporum, shows many signs of arthritis and infection. Notice the large cavity near the elbow joint that would have served to drain off the infection. (Martin Lipman/Canadian Museum of Nature)

A closer examination by Dr. Edward Iuliano, a radiologist at the Kaldec Regional Medical Centre in Richland, Wash., also found signs of arthritis. The growth rings in the bone showed that Judith likely lived with the infection for years.

Battle wounds?

The researchers also found signs that Judith suffered a similar injury and infection in its frill, including a hole similar in size and shape to one of its horns. That has led Mallon to speculate that Judith was gored by another member of its species, although there isn't really good evidence to support the theory. What scientists do know is that horned dinosaurs lived in herds and likely had a social hierarchy within their group.

"It might be that these were two rivals competing for dominance," Mallon said.

A map shows the location where Judith was found. (Canadian Museum of Nature)

Judith's bones showed that it wasn't growing much when it died, suggesting it was an adult of at least 10 years old at the time, despite its troubles.

"She was of robust constitution, I like to say — very resilient," Mallon said.

Mallon first learned about Judith when Shipp visited Ottawa for a conference in February 2015 and arranged to meet with him. Shipp wanted to find Judith a home at a museum and was impressed with the Canadian Museum of Nature's collection of horned dinosaurs.

He was impressed by the careful way Judith was collected, with all the key data intact, such as the exact position of each bone with the rock layers – important information that is often lost when amateurs collect fossils.

The Museum of Nature rarely buys dinosaur fossils, only once every few decades. "It has to be an exceptional case," Mallon said.

But it decided to purchase Judith for roughly the cost of her excavation, about $350,000.

"This was a very, very fair price as far as I'm concerned," Mallon added.

He and his team spent the next year studying the new species, and have published their findings in the journal PLOS ONE.

Judith goes on display to the public at the Canadian Museum of Nature on May 24.

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