A Look Into Nebraska's Deep Fossil History

Nov. 25, 2016, 6:45 a.m. ·

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Twenty years ago, a farmer in western Nebraska came upon the bones of a prehistoric elephant in his gravel pit. Learn how that discovery fits in to Nebraska’s rich paleontological history.


George Corner spends his days surrounded by the bones of Nebraska’s past. The long, long past—like millions of years. He’s collection manager at the University of Nebraska State Museum.

“I've been on staff for 47 years. I'm as old as some of these fossils,” Corner said with a smile. He’s an expert in Nebraska’s rich fossil record. In a room full of shelves of bones, he shows off one particular skeleton. “This is a really old animal, and old individual. The wisdom tooth, which is the only tooth left in the jaw, it's practically worn out.”

Corner remembers the fossil’s discovery, and its subsequent excavation, twenty years ago.

It was in the fall, in November 1996. Sitting at his kitchen table, Jerry Williams, a farmer from Trenton, tells the story of the fossil discovery. He was collecting gravel from a pit in his pasture to repair roads around his farmstead.

Jan and Jerry Williams, who found the stegomastodon on their property in 1996.

A local artist painted a collage for the Williams to commemorate the finding, using photos taken during the excavation.

A photo of the Williams and paleontologist Mike Voorhies during the excavation in 1997, part of a scrapbook they have from the dig.

Part of one of the original thigh bones discovered on the Williams's property. It now resides in a display about the fossil discovery at the Massacre Canyon Monument visitor's center near Trenton, Nebraska.

(Photos by Ariana Brocious, NET News)

“And when I dumped out the one load, well there was a big round thing rolled out about the size of a basketball. And first thing I thought, maybe it was a skull and then I could see that it wasn't, and of course it was way too big a bone for any cow or horse or any domestic animal that we may have had around,” Williams said. So he called his friend Tom Baker.

“And I told Tom, I think I just found a dinosaur. Tom said, nah, bet it was an elephant,” Williams said.

He was right. Williams had uncovered the bones of a primitive elephant that lived about a million and a half years ago. The following spring, George Corner and University of Nebraska paleontologist Mike Voorhies brought a team out to western Nebraska to do the excavation. Prehistoric elephant fossils have been found in almost every county in Nebraska, so at the start, they didn’t think their discovery was especially significant, Williams said.

“But then one day, they found the jaw bone. And of course, immediately when they found the jaw bone they could identify what species it was. And they got all excited,” Williams said.

The jaw bone belonged to a stegomastodon. While other stegomastodons had been discovered in Nebraska, none were as complete as this fossil. In addition to the jaw bone, they uncovered the skull, tusks, and most of the rest of the skeleton—a significant finding.

“By the time they went ahead and excavated it all, they were able to recover 80 percent, about, of it, which is more complete than any of the elephants in Elephant Hall down at the University of Nebraska,” Williams said. Locals volunteered their time and help to the effort, including one friend of the Williams who used his crane to load the 1200-pound skull into the back of Corner’s truck. The Williams donated the skeleton to the university.

These prehistoric elephants, Corner said, were probably as tall as a modern Indian elephant, and weighed several tons.

“They're built more like a bulldog than they are an elephant, if you want to look at it that way. The legs are extremely robust as you can see here. The limb bones are really, really thick,” Corner said, showing off the stegomastodon bones in Nebraska Hall.

The ancestors of these elephants came over to North America from North Africa and Central Asia three to four million years ago, Corner said. At the time this stegomastodon was alive, during the Pleistocene, Nebraska was much warmer.

“You can probably visualize the African savanna as perhaps being an analog, that's about as close as we can get today,” Corner said. Of course the climate has changed since then, Corner notes. “In a million years things change quite a bit. This whole planet is extremely, it's not static, it's extremely active. We're just newcomers to the whole thing.”

Prehistoric Nebraska was home not only to elephants, but also camels, horses, rhinoceros, even ground sloths. Corner said all of these mammals and more are preserved in Nebraska’s unique and comprehensive fossil record.

“For the last 36 to 37 million years of geologic history, we have as complete a record as there is in North America. So that's why institutions, museums from all over the world have fossil mammals exhibited that were collected right here in the state of Nebraska,” Corner said.

George Corner, vertebrate paleontology collection manager at the University of Nebraska State Museum.

Clippings of news articles following the discovery twenty years ago.

(Photos by Ariana Brocious, NET News)

The other fossils found at the site: including frogs, minnows, and beavers, reveal much more about what the climate was like than the elephant does. That broad and complex record makes post-excavation research exciting too, “the thrill of discovery continues long after the material's collected,” Corner said.

Not far from their house, Jerry and Jan Williams lead the way to the spot where the stegomastodon was found, which Jerry occasionally still uses as a gravel pit.

“So the actual dugout part that you see, where the walls are, that’s where, when they went down and found it,” Jerry Williams said. “The pieces I found would have been up on the sloping ground right there. But it’s just like he laid down right there and there he was.”

“And everybody asks us, well were there more found down here? No. It was an isolated case, he was probably down here on the Republican River bottom because there was water here at this time,” Jan Williams said.

Nebraska’s location on the mid-continent and its proximity to the Rocky Mountains is part of why the fossil record here is so great. As the Rocky Mountains eroded, rivers carried sediment down out onto the plains to the east, Corner said. “It was that material that buried these great vertebrate collections that we have here in Nebraska. Jerry's stegomastodon is really wonderfully preserved.”

“We laugh because the only really thing that was damaged was the end of his tusks which had been chewed by prehistoric prairie dogs,” Jan Williams said. Jerry Williams said he’s still in awe of the luck of their find twenty years ago. As a kid he used to go sledding down the same hill where the stegomastodon was found.

“And I often stop and thought about how many times I went over the top of this big old elephant, didn't know he was down there, he wasn't very far away. But eventually he showed up,” Jerry Williams said.


Watch the NET Television original documentary Paleo Sleuths airing Monday, November 28th at 7 PM on NET Television, Tuesday, November 29th at 8 PM on NET-2, Sunday, December 18th at 1 PM on NET Television and Wednesday, December 21st at 10 PM on NET Television. Find more about the documentary, including educational resources, at the Paleo Sleuths website.