This 14 cm long reptile provides new clues to the last years of the city, which was in the process of reconstruction after an earthquake in 62 AD.
The pregnant female, of the species "Testudo hermanni", appears to have moved into a ruined and unused store to lay her egg, but she died before laying eggs.
"The animal's intrusion went unnoticed by those responsible for the renovation of the store, and its remains were covered up," the archaeological site said in a statement on Friday.
During the reconstruction of the city, "some spaces were so little used that wild animals could move there, enter them and look for a place to lay eggs", explained the director general of Pompeii, Gabriel Zuchtriegel.
The turtle was discovered near the Stabian thermal baths, which were enlarged after the earthquake.
The eruption of Vesuvius nearly 2,000 years ago devastated the ancient city, burying it in volcanic ash.
These sediments made it possible to preserve many buildings almost in their original state, as well as the bodies of the victims of Vesuvius.
Pompeii is the second most visited tourist destination in Italy after the Colosseum in Rome.
© 2022 AFP