Hi DrDJDavidJ, thanks for your sighting. It looks like the location information you provided is incorrect. This can occur if the GPS sensor in your device was having a bad day. Please review and update the location of this record when you get a chance.
I think neither leaves nor fruits fit Acaena - the leaves of the Sheep burr that I know are basal and, elongated, and fruits are clustered along spike; a pic of whole plant might be helpful. BTW are A ovina and A echinata synonyms? we listed both on our flora list for Mt Majura; the census which I follow when I update our list has only A. ovina.