Archaeologists in Iowa have uncovered parts of a mastodon fossil, including the skull, that they believe dates back to the time when humans first walked the Earth.
Over the course of a 12-day excavation, staff from the University of Iowa’s Office of the State Archaeologist worked with members of the local community to recover the bones. According to a university press release, about 20 fragments were found, including a skull, rib bits, vertebrae, a foreleg bone and a kneecap, all believed to be from the same mastodon.
The fossils were found in an eroded creek bed on private property in Wayne County, a rural area in the south of the state. The OSA said the find was Iowa’s “first well-preserved mastodon.”
Using radiocarbon dating, researchers were able to estimate the mastodon’s age to be about 13,600 years old. According to the university, this means it must have lived at a time when humans lived and hunted in the area.
Now researchers are turning their attention to finding evidence of human interaction with this mastodon. During the excavations, archaeologists found man-made artifacts such as stone tools. Although these date from several thousand years after the mastodon skull, they indicate “human existence in the stream’s catchment area,” which has never been documented before, the press release states.
“We really hope to find evidence of human interaction with this creature – perhaps the projectile points and knives used to kill the animal and initially dismember it,” Iowa State archaeologist John Doershuk said in a statement. “There is also potential evidence on the bones themselves – there could be recognizable cut marks.”
Mastodons were large mammals related to elephants and mammoths that roamed North America about 3.5 million years ago before becoming extinct 10,500 years ago, shortly after the last ice age, according to the university’s publication. Some scientists attribute their extinction to climate change and human predation.
Archaeologists first became aware of the possible existence of the bones in 2022, when a Wayne County resident contacted Doershuk: Someone they knew had stumbled upon an unusually long bone stuck in the creek bed.
The bone turned out to be a mastodon femur, prompting archaeologists to return last fall and continue their investigation. During their stay, they also discovered a broken tusk protruding from the creek bed that they believed was likely still attached to a skull, according to the university. After securing funding, the team was finally able to complete its dig this month.
Kirk Murray / University of Iowa
Doershuk described the tusk as a “treasure trove of biological data about the animal” that could provide information about the mastodon’s age, sex and diet.
After the mastodon bones are analyzed and preserved by university scientists, they will be exhibited at the Prairie Trails Museum in Corydon, Iowa.
Mastodon fossils are relatively common in North America. In June 2023, a woman found a mastodon molar while walking on the beach in California.
