Modern rhinos aren’t Nebraskan animals. And they aren’t North American animals, either. But millions of years ago, rhinos were. In the Middle Miocene, Teleoceras major rhinos lived across Nebraska and across much of North America, too.
Analyzing an assembly of T. major remains, which were buried in volcanic ash in northeastern Nebraska around 12 million years ago, a team of researchers recently revealed that these rhinos lived relatively social and sedentary lives. In fact, as reported in a study in Scientific Reports, the team’s results suggest that these rhinos lived in huge non-migratory herds.
“I am not surprised that the analyses very strongly suggest that [T. major] lived in herds given that this animal resembles [the] modern hippopotamus in form,” said John Payne, a biologist who works with rhinos and was not involved in the study, according to a press release. “Hippos live in herds of several tens of animals — with several herds in one geographical area.”
Read More: The Last of North America’s Great Rhinos That Evolved 55 Million Years Ago
Ancient Rhino Remains Found in Ashfall
Back in 1971, a team of researchers stumbled across a massive assemblage of bones — what appeared to be the remains of over 100 T. major rhinos. Found in Nebraska’s Ashfall Fossil Beds, the remains were discovered around a dried waterhole and were apparently buried by ash after an eruption of the Yellowstone volcano in Wyoming around 12 million years ago.
But what wasn’t apparent, however, was why so many animals were found together in the same spot. Were the rhinos there because they were fleeing from the volcano? Were they there because they were seeking shelter and just so happened to meet with other members of their same species? Or were they already together — already in the area as a single herd — when the volcano began spewing its ash?
Hoping to find out, a team of researchers turned to the isotopes of the rhinos’ teeth, which carry signatures of their movements across the North American landscape. “We found they didn’t move very much,” said Clark Ward, a study author and a master’s graduate from the University of Cincinnati, according to the release. “We didn’t find evidence for seasonal migration or any evidence of a response to the disaster.”
Built like barrels and equipped with short, stubby legs, it makes sense that T. major showed no signs of a seasonal migration or a volcanic response. They were shaped like hippos, which tend to stick to the same water systems, and they probably lived like hippos, too, spending more time in and around the water than traversing the land.
Read More: Horses, Sloths, and Other Mammals Fell in the Same Sinkhole 500,000 Years Ago
Reconstructing Ancient Rhino Lives
Of course, the fact that the rhinos didn’t move in response to the volcano meant they were met with the volcano’s ash. Indeed, the dust and debris from Yellowstone traveled the hundreds of miles to Nebraska, where it fell from above and for an extended period of time, even after the eruption was finished.
“That ash would have covered everything: the grass, leaves, and water,” said Ward, now a graduate student at the University of Minnesota, according to the release. “The rhinos likely weren’t killed immediately like the people of Pompeii. Instead, it was much slower. They were breathing in the ash. And they likely starved to death.”
Prior to the eruption, the rhinos fed on grasses, and it was the traces of those grasses that allowed the researchers to recreate their lifestyle. Indeed, the vegetation that the rhinos ate and the soil and bedrock that supported that vegetation shared similar ratios of carbon, oxygen, and strontium isotopes, and those isotopes made their way to the rhinos’ teeth during feeding. By assessing the ratios of isotopes that ended up in the rhinos’ teeth, the researchers were able to determine where the rhinos ate and, thus, where the rhinos lived.
In addition to revealing the rhinos’ range, these isotopes also revealed several factors about the climate conditions that the animals encountered in their lives. While carbon isotopes told the researchers about the environment’s plants, oxygen and strontium isotopes told them about the environment’s precipitation and soil.
“I’m honored and privileged to have my name in science attached to the site,” said Ward, who worked at the Ashfall Fossil Beds as an intern and who visited the beds as a child, according to the release. “As someone who used to go to Ashfall as a kid, it’s come full circle.”
Read More: Fierce but Friendly, These Fossil Triceratops Stuck Together
Article Sources
Our writers at Discovermagazine.com use peer-reviewed studies and high-quality sources for our articles, and our editors review for scientific accuracy and editorial standards. Review the sources used below for this article:
Scientific Reports. Enamel Carbon, Oxygen, and Strontium Isotopes Reveal Limited Mobility in an Extinct Rhinoceros at Ashfall Fossil Beds, Nebraska, USA
University of Nebraska State Museum (Ashfall Fossil Beds). From Waterhole to Rhino Barn
Palaeogeography, Palaeoclimatology, Palaeoecology. Home on the Range: A Multi-Isotope Investigation of Ungulate Resource Partitioning at Ashfall Fossil Beds, Nebraska, USA
Sam Walters is a journalist covering archaeology, paleontology, ecology, and evolution for Discover, along with an assortment of other topics. Before joining the Discover team as an assistant editor in 2022, Sam studied journalism at Northwestern University in Evanston, Illinois.
