Against growing synonymy: Identification pitfalls of Hepatozoon and Schellackia demonstrated on North Iranian reptiles

•Two Hepatozoon and two Schellackia species are detected in Iranian reptiles.•Hepatozoon colubri and Hepatozoon ophisauri are redescribed based on new data.•An overview of reptilian Hepatozoon and Schellackia species so far known is provided.•Artefacts caused by blood smear processing are identified.•Important pitfalls are identified preventing resolution the taxonomic disorder.