ERP149953 PRJEB64788 b6262561-007c-49ed-afbe-e48ca1ba216f ancient DNA from Medieval guinea pig The mandible of a guinea pig (Cavia porcellus) was found in osteological material collected during archaeological excavations at Ojców Castle (southern Poland). The bone fragment was radiocarbon dated and subjected to ancient DNA (aDNA) testing. The age of this guinea pig mandible fragment was directly dated between the late 16th and the early 17th century. The radiocarbon dating results are compatible with dating based specimens stratigraphic position. The ancient DNA analysis confirmed the taxonomic identification and indicated possible routes of introduction of this species into Europe. Given the high-status of the castle's possessors in the 16–17th centuries we reason that the single guinea pig bone in Ojców belonged to a pet. Guinea pig remains from the XVIth century Ojców Castle (southern Poland) The mandible of a guinea pig (Cavia porcellus) was found in osteological material collected during archaeological excavations at Ojców Castle (southern Poland). The bone fragment was radiocarbon dated and subjected to ancient DNA (aDNA) testing. The age of this guinea pig mandible fragment was directly dated between the late 16th and the early 17th century. The radiocarbon dating results are compatible with dating based specimens stratigraphic position. The ancient DNA analysis confirmed the taxonomic identification and indicated possible routes of introduction of this species into Europe. Given the high-status of the castle's possessors in the 16–17th centuries we reason that the single guinea pig bone in Ojców belonged to a pet. ENA-FIRST-PUBLIC 2023-08-05 ENA-LAST-UPDATE 2023-08-05