Bats May Have Begun Flying 65 Million Years Ago, New Study Finds

Bats may have taken to the skies in Europe about 65 million years ago, roughly a million years after an asteroid strike wiped out the non-avian dinosaurs, according to a major new study combining bat genomes and fossils. The research also suggests that echolocation, the biological sonar bats use to navigate and hunt in darkness, appeared very early in their evolutionary history.

Published this week in Nature, the study analyzed high-quality genomes from 103 bat species across all 21 recognized bat families, along with fossil evidence from 44 ancient bats. The researchers say the combined evidence helps resolve several long-running questions about where bats came from and how their unusual abilities developed.

A new origin story for bats

Scientists have struggled to reconstruct the earliest history of bats because the fossil record is incomplete and previous genetic studies have produced conflicting answers. Earlier research had proposed Africa, Asia and North America as possible places where the first bats appeared.

The new analysis points instead to Europe during the late Paleocene, around the time mammals were expanding into ecological spaces left open after the dinosaur extinction. The researchers also found evidence that major bat groups later spread into other parts of the world.

The study is based on an unusually large genetic dataset. Researchers created 42 new chromosome-level genome assemblies and combined them with 62 existing high-quality assemblies, giving them data from 103 bat species.

They also examined 699 physical characteristics across 65 species, including 44 extinct bat species, and combined that information with genetic data. This allowed the team to build a more detailed family tree covering both living and extinct bats.

Flight and echolocation appeared surprisingly early

One of the study’s biggest findings concerns echolocation.

Many bats use high-frequency sounds and listen for the returning echoes to locate objects, find prey, and move through darkness. The researchers found that the fossil Vielasia belongs to the oldest group of bats identified in their analysis, supporting the conclusion that laryngeal echolocation existed before modern bats diversified.

That means two of the abilities that define bats today, powered flight and echolocation, may have developed very early in their history rather than appearing much later.

Sonja Vernes, a professor of biology at the University of St Andrews in Scotland and one of the study’s leaders, explained why the combination could have been so useful.

“I think being able to do both, fly and echolocate, opens up the most amazing opportunities to move into new niches – hunting at night when there’s less competition and fewer predators, for example. Flight got them into the air. Echolocation let them own the night,” Vernes said, according to Reuters.

Emma Teeling, a zoology professor at University College Dublin and another study leader, said echolocation may have allowed bats to exploit nighttime environments.

“Echolocation allowed bats to become nocturnal, essentially, and not compete with birds or be preyed on by diurnal (day-active) birds,” Teeling said.

What happened after the dinosaurs disappeared

The study places the likely origin of bats in Europe during the late Paleocene, following the asteroid impact about 66 million years ago that caused the mass extinction at the end of the Cretaceous.

The researchers say bats later spread into other regions. Their analysis indicates that one major group, Yinpterochiroptera, originated in Africa during the early Eocene before later dispersing into Asia and Europe, while Yangochiroptera most likely originated in Europe around a similar period.

The research also suggests bat groups diversified during the Paleocene-Eocene Thermal Maximum, about 56 million years ago, when global temperatures rose and environments changed significantly.

Bats are more unusual than they look

There are now more than 1,500 known bat species, making up more than one-fifth of all living mammal species. They live across much of the world and have developed very different diets and lifestyles, including eating insects, fruit, nectar, fish and blood.

They are also the only mammals known to have evolved powered flight. Their wings are modified forelimbs, with greatly elongated fingers supporting a thin skin membrane.

The study could also help researchers investigate other unusual bat traits. Some bat species live exceptionally long lives for their size, show strong resistance to certain diseases and can carry viruses without becoming visibly ill. The researchers say the new genomic data could eventually help scientists study the genetic basis of aging, immunity and disease resistance.

Teeling told Reuters that the work could eventually have implications beyond bats.

“This work could eventually inform human research into aging, immunity and disease resistance,” she said.

The researchers say their new genome and fossil-based family tree do not answer every question. The ancestors of bats remain poorly understood, and scientists still need older transitional fossils to determine exactly how flight and echolocation developed.

But the study provides a much clearer timeline: bats likely emerged in Europe around 65 million years ago, and some of the abilities that made them successful in the night sky were already developing near the beginning of their evolutionary story.