@donhe I think so, I looked at a video that I took of the caterpillar and I saw a little of a black spot at the edge of the caterpillar, though I think this could be the centre of the segment.
In this photo: the black spot is on the upper right side caterpillar's first abdominal segment. Can you take a frame from the movie showing its left side, and add it to this sighting ?
@donhe I took 2 bad photos of the video. I couldn't do a screenshot since my laptop was malfunctioning. The cursor is pointing to the black spot. I hope it helps.
Thanks. That spot is ventral, and the original photo shows a dorsal spot, so they do not appear to be related pigmentation, which would have been useful for an ID, like the pair of black spots on Didymoctenia exsuperata larvae, see http://lepidoptera.butterflyhouse.com.au/enno/exsuperata.html So possibly the marks are wounds from parasites, or just sticky dirt.
I believe it to be E. excursaria for 2 reasons. 1. I think I can see two dorsal horns on the rear. 2. I have also seen a moth of that species nearby. See Ectropis excursaria (Common Bark Moth)
See photos of E, excursaria caterpiilars here: http://lepidoptera.butterflyhouse.com.au/enno/excursaria-e.html I'm not sure they match your caterpillar.