First paleoparasitological evidence of Muellerius sp. in sheep or goat dated to the Sasanian Empire (500 CE) in ancient Iran.

A fecal pellet was recovered in an ancient salt mine in Chehrabad located in western Iran (36.55° N, 47.51° E). Based on prior publications showing the success of the salt mine's environment to preserve various life forms, it was decided to try and ascertain whether this faex contained any parasites of paleoparasitologic interest. The rehydration involved placing the pellet in an aqueous solution of 0.5% trisodium phosphate for a week, followed by the examination of aliquots of the entire rehydrated sample on a total of 153 microscope slides. The examination of the rehydrated material revealed the presence of two larval nematodes; there were no eggs or oocysts recovered. The larvae were photographed and measured, and the decision was made not to submit the two larvae to grinding and DNA extraction for molecular diagnostics due to their excellent state of preservation. The larvae were identified as first-stage larvae that appear to represent the genus Muellerius. Herein are reported the finding of two first-stage larvae of Muellerius nematodes (Metastrongyloidea, Protostrongylidae) from the rehydrated fecal pellet collected in a Chehrabad salt mine from the era of the Sasanian Empire.