In near-complete fossil form, only known Kansas dinosaur reappears after 100 million years

LAWRENCE — In May of 1955, a Kansas rancher on horseback was checking on cows and calves near a dry “pasture ditch” that ran through his land in Ottawa County. In a gully, he spotted something strange — fragments of unusual bone embedded in a rock. The rancher, named Warren Condray, recognized this could be important.

Years later, Condray’s son Jettie recalled the discovery: “There was an oval-shaped chalky structure on the surface of the rock. As I remember, the oval-shaped bone was about four or five inches long and perhaps one and one-half inches wide. After dad’s discovery, I, as a 10-year-old, went to the site about a quarter mile from our house in a pasture. I carefully looked over the creek’s edge and saw it.”

After showing his son the find, the rancher Condray called his state senator to report it.

“Next, the senator contacted our museum — and somebody from the University of Kansas went out and collected it,” said David Burnham, preparator with KU’s Biodiversity Institute and Natural History Museum. “It was published in 1960 as a new species. It’s fairly complete for a dinosaur.”

To date, Silvisaurus condrayi (named for the rancher) is the only known dinosaur that inhabited what today is the state of Kansas. 

Scientists from KU had collected the skull, a lower jaw, teeth, neck bones, ribs, shoulder spikes, backbones, a tailbone, a leg, part of the pelvis and other bits of the creature from the Condray ranch. But only part of the dinosaur ever was placed on exhibit at the museum, and that display was removed several years ago. 

But this spring, Silvisaurus made a triumphant return to the museum in a new, more complete form, accompanied by an interactive display that includes stunning depictions of the dinosaur and its environs from KU scientific illustrator Oscar Sanisidro.

“The display has been refurbished,” Burnham said. “When we were approached about redoing the exhibit I said we have most of the skeleton and it could be mounted. We have very talented exhibitors, and they were able to produce an armature to put the bones on. Oscar came up with the illustration of the dinosaur and the environment it lived in, with the leaves and the trees and interior seaway not too far off in the distance.”

The display also features a section of the Silvisaurus’ armor — a key feature of the dinosaur’s morphology — allowing museum visitors to feel the texture of the plating.

“Silvisaurus was like a tank covered with bony plates,” Burnham said. “These bony plates are armor, but they may have other functions. They have horns and spikes all over their bodies and a huge shoulder spike. We don’t have the full body or the tail — but it would have had some armor along its tail.”

The fierce appearance of 3-foot tall, 10-foot long Silvisaurus belied its gentle herbivory lifestyle. According to Burnham, Silvisaurus was an “armadillo on steroids.”

Burnham said the dinosaur’s armor would have been needed to fend off potential aggressors.

“There probably were predators that lived back then,” Burnham said. “They didn’t have T. rex, but they had other large meat-eating dinosaurs that could have preyed on Silvisaurus if they could have flipped it over and gotten to its belly. Silvisaurus would have squatted down and wouldn’t have had to worry about it.”

Condray’s ranch, where the dinosaur was unearthed, included sections of Dakota Formation, sedimentary rock left behind on the east coast of the Late Cretaceous Western Interior Seaway.

“Picture Kansas, and if you draw a line right down the middle of the state from north to south, everything on the east would have been land and everything west would have been water — from the Gulf of Mexico to the Arctic,” Burnham said. “Silvisaurus condrayi means 'lizard of the forest.' It got that name because it lived on wooded beachfront property in Kansas 100 million years ago.”

Kansas at that time would have been warmer, wetter and lusher, Burnham said.

“The forests were pretty dense,” he said. “The climate was warmer. There was so much water, and the storm events were probably worse than they are today. It was totally forested, and the whole eastern part of the state would have had some deltas.”

While the Silvisaurus condrayi fossil is the only one of its kind ever discovered, there is another possible trace of the species, also in the collection of the KU museum.

“They found a track site nearby that could have been made from this dinosaur’s footprints,” Burnham said. “We have the footprints here — it’s a slab of rocks that fit together. We assembled it and put in on exhibit in Chicago’s Navy Pier for Dinofest.”

In addition to delighting museumgoers, the sole-known Kansas dinosaur has aided scientists trying to deduce relationships between Silvisaurus and its cousins.

“If you look at the family tree of this group of dinosaurs, this is probably one of the more primitive ones — somewhere near the base of that tree,” said Burnham. “But it provides a key point in the evolutionary history when these things were starting to evolve 100 million years ago. It allows us to better understand dinosaurs that came later and how they fit into the tree of life.”

The Kansas dinosaur also has served the subject of academic work by scholars and KU graduate students, helping to train generations of paleontologists at KU. Some even have made new discoveries about Silvisaurus condrayi.

“One former student from KU named Larry Whitmer did his master’s here — now he’s at Ohio University,” Burnham said. “He had been CT scanning dinosaur skulls and found there are internal chambers and air passages in relatives of Silvisaurus skull. Some people think it may have been for communication. They could have made an air call, like a hoot or a holler — or maybe a warning. Really, who knows what dinosaurs talk about?”

The public can visit Silvisaurus condrayi during museum hours. 

PHOTO: For the new Silvisaurus condrayi exhibit, KU scientific illustrator Oscar Sanisidro created a large-scale depiction of the Kansas dinosaur and the lush environment it once roamed. Credit: Oscar Sanisidro.