The earliest primate ancestors may have been cold weather survivors, not tropical tree dwellers. A study published in June 2026 by researchers including Jorge Avaria Llautureo of the University of Reading found that the first primates likely evolved in cold, dry parts of North America, not in warm tropical forests as scientists long assumed. Some of these tiny creatures may have even survived seasonal Arctic conditions by slowing their metabolism or hibernating.
A tiny tree dweller that braved the cold
One of the earliest known primates was Teilhardina, a creature weighing just 28 grams, about the same as the smallest living primate, Madame Berthe's mouse lemur. Teilhardina appeared around 56 million years ago, roughly 10 million years after the dinosaurs went extinct. It had fingernails instead of claws, a key primate trait that helped it grasp branches and handle food. Its diet was high calorie, consisting of fruit, gum, and insects. Fossils show that Teilhardina dispersed rapidly from its origin in North America across Europe and China.
Why scientists had it wrong for so long
Most primates today live in the tropics, and most primate fossils have been found there. That led researchers to assume early primates evolved in warm, wet environments. But the new study used fossil spore and pollen data from early primate fossil sites to reconstruct past climates. The results showed those locations were not tropical at the time. Instead, early primates lived in cold and dry regions. The study also found that warmer global temperatures did not speed up primate evolution or spread. However, rapid shifts between dry and wet climates did drive evolutionary change.
What this means for understanding our own origins
The findings overturn decades of assumptions about where and how the primate lineage began. The same forces that shaped early primates, including dramatic climate shifts, continue to shape life on Earth today. As the planet warms, lessons from the past become more relevant. It took millions of years before primates colonized the tropics. The cold, not the heat, may have been the crucible that forged our earliest ancestors.
