Well adjusting my criteria to fit with the samples and wiki, I think I've found a couple of crater chains here.
Once again very small images but halfway down the rille (which mabe itself fits the description?) there's a
fairly large boulder with tracks above it and alongside it, and just a little lower is what looks like a spinal protuberance.
Well I really don't know, but I'm sure that the first shot of the images which I look at is larger scale than the above one, which isn't a thumbnail. I can assure you that my eyesight really isn't that
Ah! That's better...I increased the height to 600, so I'll do that for those which come out too small in future