Any insight to the origin of this bowl will be greatly appreciated. It's big: 21" by 14" at the top, and heavy 12.5 pounds. The sides are 1.5" thick. It has a design of painted on whales and is covered in some kind of hide and because of the design we speculate that it could be whale hide. Our best guess is that it is clay or earthenware underneath the hide. There is no artist signature or mark that we could find. Anyone seen anything like this before? Many thanks for any help and happy treasure hunting!