These were made by Joanne Dhody of Design Unlimited and Osteographica. She is the mother of Anna Dhody, the curator of the Mütter Museum in Philadelphia, PA.
These are both very beautiful. I love the variations in shades with each leaf. I attempted to make one using seed pods and I know it's a tedious process, so I commend Joanne for making these skulls. As there is snow on the ground and bare trees here, I thought a burst of color would be a nice change.