New research indicates that the earliest primates originated in cold and dry regions of North America rather than tropical forests. The findings challenge long-held assumptions about primate evolution.
A study published in the Proceedings of the National Academy of Sciences in 2025 maps the origins of primate ancestors using fossil and climate data. Researchers led by Jorge Avaria-Llautureo of the University of Reading found that early primates lived in cold, dry areas and later spread to other regions.
One of the earliest known primates, Teilhardina, weighed about 28 grams and appeared around 56 million years ago in North America. Fossils show it had fingernails instead of claws, a trait still seen in modern primates. Species dispersed rapidly across Europe and China.
The analysis shows that rapid shifts between dry and wet climates drove evolutionary changes more than warmer temperatures. Some early primates may have survived seasonal Arctic conditions by slowing their metabolism or hibernating.
The study was based on fossil spore and pollen data from early primate environments. It suggests that changeable conditions favored mobile ancestors that could seek new habitats.