I think these are all the same fly, but I've left it too long to remember clearly. Conioscinella I think.
Bone-skater fly Piophilidae on long-dead wallaby, The Steppes, Tasmania, March 2020
I think these are all the same fly, but I've left it too long to remember clearly. Conioscinella I think.
Wrack-fly Fucellia tergina (Anthomyiidae), Alum Cliffs, Taroona, Tasmania, May 2015
Mass of Kelp Flies (Chaetocoelopa sydneyens) on rocks just above high tide at Muttonbird Island (Coffs Harbour) on the north coast of NSW Australia.