Occurrence of Taeniidae in a Middle Pleistocene speleothem of the Bàsura cave (Toirano, Liguria, Italy)

Objective: This study aims to (i) analyse whether speleothems may contain fossil parasitic worm eggs and, if so, (ii) identify the pathogens involved, and (iii) place them in geological, palaeontological, and chronological contexts to know the zoonoses that could affect human and animal populations during the Middle Pleistocene.
Materials: A sample of calcite dated to the beginning of MIS 9 and MIS 8 from the Bàsura cave (Liguria, Italy) was analysed.
Methods: The chemical protocol applied is characterised using hydrochloric acid, the reduction of hydrofluoric acid application time, and by the absence of the use of base, dense liquor or acetolysis.
Results: An embryophore of a taeniid was recovered.
Conclusions: Endoparasitic worm eggs can be found in speleothems. A taeniid embryophore was found in a calcite level dated to MIS 9. Zoonoses related to the Taeniidae family existed 300,000 years ago in the northern Mediterranean region and may have affected Middle Pleistocene predators, carnivores, or humans. Speleothems are good tools for paleoparasitological studies.
Significance: This is the oldest taeniid recovered and identified.
Limitations: A more precise determination of the genus of this taeniid is not possible in the absence of more precise palaeontological data.
Suggestions for further research: An application of this approach to other Pleistocene speleothems could broaden the spectrum of parasites and their zoonoses over remote Pleistocene periods.