Eimeria leuckarti in equid coprolites from the Sassanid Era (2nd-6th century CE) excavated in Chehrabad Salt Mine archaeological site, Iran

Objective: This study reports coccidian oocysts in an equid coprolite dated to the Sassanid Empire (2nd-6th century CE) recovered in Chehrabad Salt Mine archaeological site, Iran.

Methods: Between 2015 and 2017, an archaeoparasitological investigation led to the discovery of an equid coprolite in the Chehrabad Salt Mine archeological site, (Douzlakh), western Iran. Samples were rehydrated using trisodium phosphate solution and were examined by light microscopy.

Results: Seven oocysts of Eimeria leuckarti (Flesch, 1883) were identified; they were in various stages of sporulation.

Conclusion: This is the first report of ancient coccidian oocysts from equids. The importance of this observation is discussed, and current knowledge of eimeriid oocysts at archaeological sites is reviewed.

Significance: The observations of E. leuckarti increases current knowledge of parasite biodiversity in ancient Iran when it rested along the Silk Road, a network of trade routes connecting the East and West that was central to economic, cultural, political, and religious interactions between these regions, and to livestock movement that could contribute to the transmission of the parasites from/to other regions.

Limitations: The contextual information about animal species present in and around the Salt Mine during its working periods, including Achaemenid dynasty (6th to 4th century BCE) and Sassanid era (2nd to 6th century CE), is very limited and does not allow secure conclusions regarding the host origin of the coprolites.

Suggestions for further research: Application of molecular biology tools to identify the correct host origin of the coprolites and to detect more parasite species is advocated.