Megarthrus stercorarius Mulsant et Rey, 1878
Megarthrus franzi Scheerpeltz, 1947


The nominal taxon franzi has been placed in the synonymy of the present species by Cuccodoro and Löbl (1997). I am not entirely convinced by this synonymy, because (1) the two taxa show a disjunct distribution pattern and may therefore be genetically separated at least at the subspecies level, and because (2) there is some variability in the shape of the male genitalia that may correspond to the two (or even more) disjunct populations. I suspect that Megarthrus stercorarius is actually a complex of 2 to 4 (sub-)species in the Pyrenees, Alps, Carpathians and Caucasus, but I provisionally accept the synonymy suggested by Cuccodoro and Löbl (1997) until more data on this issue become available.