A sweeping new analysis of bat evolution is overturning one of mammalogy's most enduring mysteries, suggesting that the ancestors of today's bats first emerged in Europe roughly 65 million years ago, near the dawn of the age of mammals after the extinction of the dinosaurs.
The study, published in Nature, combines reference genomes from living bats with fossil evidence to reconstruct a far more detailed evolutionary history than scientists have previously been able to assemble. The result is a revised family tree that not only reshapes the timing of bat diversification, but also changes the geographic story of how the world's only flying mammals spread across the planet.
For decades, scientists have debated where bats originated and how their extraordinary adaptations — powered flight, echolocation in many species, and a remarkable ability to occupy ecological niches from deserts to rainforests — first evolved. The new research strengthens the case that bats arose much earlier than some previous estimates and that Europe played a central role in their early history. That conclusion is likely to reverberate well beyond bat biology, because bats are among the most important and diverse mammal groups on Earth, with more than 1,400 species.
The study's significance lies in its method as much as its conclusion. By pairing high-quality genomic data with fossil calibrations, researchers were able to resolve relationships among bat families that had remained uncertain for years. Fossils provide the physical record of ancient life, but genomes reveal the inherited code that links living species to their ancestors. Together, the two lines of evidence allowed scientists to test competing ideas about when major bat lineages split and where those splits likely occurred.
That integrated approach appears to have produced a more stable picture of bat evolution than earlier studies based on morphology alone or on limited genetic sampling. The revised phylogeny indicates that the bat family tree is deeper and more geographically complex than previously thought. Instead of a simple origin story centered in one modern tropical region, the new evidence points to an ancient European cradle for early bats, followed by dispersal into other parts of the world as climates shifted and continents changed.
The findings also arrive at a time when researchers are increasingly using genomic tools to revisit long-standing evolutionary questions. In bats, those questions are especially difficult because the fossil record is sparse and bat skeletons are delicate, making preservation rare. That scarcity has left major gaps in the record, forcing scientists to infer much of bat history indirectly. The new study narrows some of those gaps, but it also underscores how much remains unknown about the earliest stages of bat evolution.
The implications extend into broader debates about mammal evolution after the mass extinction that ended the age of dinosaurs. Bats are one of the earliest mammal groups to achieve powered flight, and their rise may have been shaped by ecological opportunities created in the aftermath of that global catastrophe. If bats originated in Europe around 65 million years ago, their early expansion would have unfolded during a period of dramatic environmental change, when shifting climates and changing land connections were reshaping life on Earth.
The research is likely to prompt further scrutiny of fossil sites in Europe and elsewhere, as scientists look for additional evidence to support or refine the new timeline. It may also encourage new genomic comparisons across bat species, especially those representing the deepest branches of the bat family tree.
For now, the study offers the clearest picture yet of bat origins: a lineage that emerged in the shadow of extinction, diversified across a changing planet, and eventually became one of the most successful mammal groups in history. The new evidence does not just add detail to the bat story — it rewrites the opening chapter.