An elephant’s trunk is a marvel of nature: part tool, part nose, part muscle powerhouse. With it, elephants can rip branches from trees or delicately pick up a single peanut. But now, researchers have discovered something even more intriguing about these extraordinary appendages — they wear their wrinkles like a roadmap, one that reveals whether an elephant favors its left or right side.

Much like how humans are right- or left-handed, elephants have a “trunkedness.” And if you know where to look, you can tell just by the patterns of wrinkles and whiskers on their trunks, researchers say.

Why More Wrinkles Matter

It turns out, elephant trunks wrinkle in a way that’s not just random or tied to age. In a new study, researchers from Humboldt University in Berlin and the Max Planck Institute for Intelligent Systems found that the way an elephant curls its trunk to grab food shapes the lines on its skin. Over time, the side the elephant uses more frequently accumulates extra wrinkles, while the opposite side, often scuffed against the ground, grows smoother whiskers.

The researchers found approximately 10% more wrinkles on the side they bend towards more frequently.

“The wrinkle effect is more subtle, but still significant,” says Dr. Michael Brecht of Humboldt University, co-author of the study. “It indicates that wrinkle patterns are at least partially use-dependent.” In other words, an elephant that habitually curls its trunk to the left will have more wrinkles on that side — a sort of biological tally of its everyday habits.

But why do elephants have wrinkles in the first place? It’s not just a sign of age. Wrinkles on an elephant’s trunk help it perform feats of tremendous flexibility and dexterity rivaled only by the human hand. “The trunk is this insane, amazing, grasping organ,” Brecht told The Guardian. “It has more muscles than any other body structure in mammals.” In fact, an elephant’s trunk contains over 46,000 muscles, compared to the human body’s 600 to 700.

These muscles allow the trunk to twist, stretch, and curl in ways no other mammal can replicate. Wrinkles, it seems, help the trunk bend and stretch like the folds of an accordion. And the more wrinkles, the more flexibility. Asian elephants (Elephas maximus), which have to wrap their trunks around objects to pick them up, tend to have more wrinkles than their African cousins (Loxodonta), who use two finger-like structures at the tip of their trunks to grasp items.

“For this wrapping, the trunk needs to be more flexible, and we think that’s why they have a lot more wrinkles,” Brecht explains.

A Trunk’s Life Story

The discovery also ties into the bigger picture of elephant evolution. Asian and African elephants have long been known to differ in the structure of their trunks, but this research suggests that wrinkle patterns are another way these species have adapted to their unique environments.

The wrinkling process starts even before an elephant is born. Researchers tracked how wrinkles form in elephant fetuses using micro-computed tomography (microCT) imaging. They noted that the number of wrinkles doubles every 20 days during early development. By the time an elephant is born, its trunk already carries the beginnings of its lifelong wrinkle pattern, which will continue to develop as the animal ages and uses its trunk. “Later wrinkles are added slowly, but at a faster rate in Asian than African elephants,” the researchers noted in their study.

Wrinkles are more than skin deep, too. Scientists suspect that these patterns are tied to neurons in the elephant’s brainstem. This means the trunk is mapped out in the brain in a way similar way to human hands. It’s a complex system, perfectly designed for the many tasks an elephant performs with its trunk each day, from picking delicate leaves to moving massive logs.

A Special Structure

Mechanical engineer Andrew Schulz of the Max Planck Institute points out that elephant trunks belong to a special class of muscular structures called hydrostats, which are found in creatures like octopuses and snails. But unlike these other animals, an elephant’s trunk is covered in thick, wrinkled skin that adds both protection and versatility. Schulz notes that this wrinkled skin allows the trunk to change shape with ease, protecting it as it shifts and curls to grip objects.

MicroCT scans revealed that the skin layers within the trunk wrinkles vary significantly. While the outer layer (the epidermis) remains relatively constant, the inner layer (the dermis) changes thickness dramatically between the troughs and peaks of wrinkles. This variation, the authors suggest, could be what allows the skin to stretch so effectively while still providing protection​

The implications of this research are fascinating. Scientists now have a new way to identify and study individual elephants by simply looking at their wrinkles and whiskers. The patterns can offer clues about their behavior, environment, and even their overall health. For conservationists, understanding these subtle cues could help in tracking elephants in the wild and improving care for those in captivity.

What started as a study of skin has uncovered something deeper: the way elephants, these massive and majestic creatures, adapt to their world in ways that are both visible and hidden.

The findings were reported in Royal Society Open Science.