New research released Thursday is challenging historical timelines of our ancestors after scientists said that fossilized human footprints found in New Mexico in 2021 are actually older than previously thought. The research, published in the journal, Science, says the footprints are now most likely the oldest evidence of humans in the Americas, forcing historians to rethink when humans arrived to the area. The footprints were found in White Sands National Park, which has the largest collection of fossilized human footprints, which date back between 21,000-23,000 years. Researchers used ancient conifer pollen and quartz grains to date their discovery, after initially using the seeds of aquatic plants. The findings now put a question mark over the traditionally held belief that humans arrived in the Americas about 15,000 years ago via a land bridge between Russia and Alaska.