Skeletal remains of a "wild" female horse were discovered by landscapers in 2018, buried in a backyard in a Lehi, Utah, home.
At first, the discovery had scientists believe that the skeleton dated back 16,000 years to the last ice age. This estimate of the horse remains suggested this mare was wild. Scientists revealed that such horses lived in North America from about 50 million to 10,000 years ago. They also disappeared around the same time that other large animals, such as mammoths, short-faced bears, dire wolves and giant sloths, went extinct.
However, recent studies found that the remains are actually no older than 340 years old. The new studies suggest that the horse died when it was about 12 years old. Studies also show that the horse was domesticated and dated back to post-Columbian times after the Spanish introduced the domestic horse to the Americas, starting in the 16th century.
The researchers added in their study that any Indigenous people who lived in the Americas "swiftly integrated" these European horses into their cultures and economies. Scientists believe that this mare was likely raised, looked after and ridden by Indigenous people who lived in, now, Utah.
Study lead author, William Taylor, an assistant professor of anthropology at the University of Colorado, Boulder, said; "The Lehi horse shows us that there is an incredible archaeological record out there of the early relationship between Indigenous people and horses. A record that tells us things not written in any European histories."
The mix-up with the mare's age happened because Indigenous people buried the horse in a pit surrounded by lake sediments dating back 14,000 to 16,000 years ago.
Since a new radiocarbon sample didn't give an exact result, "we can only say that this horse died sometime after 1680."
Taylor and colleagues also found fractures on the horse's spine. This suggests that someone had repeatedly ridden the horse either bareback or with a soft saddle pad. Those fractures are a "kind of feature that is pretty rare in a wild animal." Taylor added that "Once we looked closer, we found other clues, including severe arthritis. Ultimately, genetic data helped us to confirm this idea that the horse was the domestic horse Equus caballus, not an ice age wild equid."
While analysing the isotopes (a variation of an element) in the horse's tooth enamel, scientists also discovered that the horse drank water and ate vegetation in the Wasatch Front region of Utah. This suggests that "the horse was raised and tended locally ... near where it was found."