10/18/2026
Koalas have fingertip ridges that can look remarkably like human fingerprints. Their patterns can include loops, whorls, and arches, even though koalas are marsupials and are only distantly related to humans.
Maciej Henneberg, Kosette M. Lambert, and Chris M. Leigh described this similarity in their 1997 paper, "Fingerprint homoplasy: Koalas and humans," published in Natural Science. The researchers, associated with the University of Adelaide in Adelaide, Australia, reported similarities visible both to the naked eye and under magnification.
The finding is an example of convergent evolution. This means that distant animal groups independently develop similar features in response to similar needs. The study noted that the koala and human lineages had evolved separately for at least 70 million years.
For koalas, a leading explanation involves the demands of climbing and grasping. Fingertip ridges may help with grip and fine touch when holding eucalyptus branches and handling leaves.
The resemblance also raises an interesting forensic possibility. A partial print on a surface could be confusing if an examiner assumed it must have come from a human and did not consider an animal source.
This does not mean koala fingerprints commonly cause problems in criminal investigations. The key point is that their ridge patterns can be similar enough to human ones to create potential ambiguity, especially when a print is incomplete.
