Senckenberg researchers, together with international colleagues, examined DNA traces from tortoises from Madagascar and came across a previously unknown species.
Bone finds up to 1200 years old and samples from museum specimens were analyzed.
The analysis showed that three closely related giant tortoise species originally lived on Madagascar, the neighboring island of Aldabra and the Seychelles.
Two of them were wiped out in the Middle Ages, just a few centuries after Madagascar was settled.
For the scientists, this is further evidence that humans reduced biodiversity earlier than previously thought.
The species detected for the first time, whose genome was sequenced by the researchers, reached a shell length of about half a meter.
The last surviving species from the western Indian Ocean, the Aldabra giant tortoise, is almost 1.4 meters tall.