I saw the smaller of the collared earthstars first and it was only a couple of cm tall, if it hadn't had such an obvious collar I would have actually doubted it was a G. triplex and thought had found a different Geastrum species. But then I noticed less than a foot away some more collared earthstars - all the large normal sort of size. luckily earthstars are moveable so I could place them next to each other for comparison.
Strange that this one was so small?