New Mexico mammoths among best evidence for early humans in North America
The remains of two mammoths discovered in New Mexico show that humans lived in North America much earlier than thought. Credit: NPS.

The mother mammoth and her calf were killed by human beings.

The bones from the butchering site show how humans shaped pieces of their bones into disposable blades to break down their carcasses. This site is different from other sites from this era. Most archaeological evidence doesn't place humans until tens of thousands of years later, in New Mexico.

A recent study led by scientists with The University of Texas at Austin found that the site offers some of the most conclusive evidence for humans to settle in North America early.

There was a lot of evidence found in many places. There are fossils with broken bones, bone flake knives, and signs of controlled fire. The site has a settled age of 36,250 to 38,900 years old, making it one of the oldest known sites left by ancient humans in North America.

Timothy Rowe is a professor in the UT Jackson School of Geosciences. There is a beautiful skeleton on its side. All of it has been busted up. The story is what it is.

Credit: University of Texas at Austin

The results were published in a journal.

Most of the time, Rowe doesn't research mammoths or humans. The bones showed up in his backyard. A tusk weathering from a hillslope was spotted by a neighbor. Rowe discovered a bashed-in mammoth skull and other bones that appeared to have been broken. The site looked like it was a butchering site. There are suspicions of early human sites. It's hard to determine what was shaped by nature or humans.

The question of when humans first arrived in North America has been debated. Stone-wrought tools were left behind by the Clovis culture. The evidence gets more subjective at older sites where stone tools are not present, according to retired Texas State University Professor Mike Collins, who oversaw research at Gault, a well-known archaeological site near Austin.

New Mexico mammoths among best evidence for early humans in North America
Close up of the bone pile during excavation. This random mix of ribs, broken cranial bones, a molar, bone fragments, and stone cobbles is a refuse pile from the butchered mammoths. It was preserved beneath the adult mammoth’s skull and tusks. Credit: Timothy Rowe / The University of Texas at Austin.

Rowe and his co-authors discovered an array of supporting evidence when they put samples from the site through scientific analyses.

The University of Texas High-Resolution X-rayComputed Tomography Facility found bone fragments similar to those in freshly knapped cow bones and puncture wounds that would have helped in draining grease from ribs and vertebral bones.

There are only a few ways to skin a cat. The butchering patterns are unique.

Fire particles came from a sustained and controlled burn, not a lightning strike or wildfire. Even though the site is over 200 feet above the nearest river, the burned remains of small animals, mostly fish, are still present.

  • New Mexico mammoths among best evidence for early humans in North America
    Butchering marks on mammoth ribs. The top rib shows a fracture from blunt force impact; the middle rib shows a puncture wound, probably made by a tool; the bottom rib shows chopping marks. Credit: Timothy Rowe et al. / The University of Texas at Austin.
  • New Mexico mammoths among best evidence for early humans in North America
    The excavation site mostly holds broken bones from the mammoths’ ribs and spine. The most prominent fossil is a portion of the adult mammoth’s skull. Credit: Timothy Rowe / The University of Texas at Austin.
  • New Mexico mammoths among best evidence for early humans in North America
    Butchering marks on mammoth ribs. The top rib shows a fracture from blunt force impact; the middle rib shows a puncture wound, probably made by a tool; the bottom rib shows chopping marks. Credit: Timothy Rowe et al. / The University of Texas at Austin.
  • New Mexico mammoths among best evidence for early humans in North America
    The excavation site mostly holds broken bones from the mammoths’ ribs and spine. The most prominent fossil is a portion of the adult mammoth’s skull. Credit: Timothy Rowe / The University of Texas at Austin.

Based on genetic evidence from Indigenous populations in South and Central America and artifacts from other archaeological sites, some scientists have proposed that North America had at least two founding populations.

New Mexico's age and bone tools may lend support to the theory. The study adds to a growing body of evidence for pre-Clovis societies in North America while providing a toolkit that can help others find evidence that may have been overlooked.

Collins said that Tim has done excellent work. Forging a path that others can learn from is what it is.

More information: Timothy B. Rowe et al, Human Occupation of the North American Colorado Plateau ∼37,000 Years Ago, Frontiers in Ecology and Evolution (2022). DOI: 10.3389/fevo.2022.903795 Journal information: Frontiers in Ecology and Evolution