Although found nearby, this bone has not been determined to be a part of Muffin. We believe it to be a part of Blueberry's skull. However, to date, no Haplocanthosaurus skull has been recovered. Until one is, we don't know what to look for to decide whether this is really Blueberry's skull piece. I am providing a screen saved .mp4 file for reference below:
This vertebra is also a part of Blueberry: