I’m blogging today about a piece of information about cylinder seals I ran across in a children’s nonfiction book on Mesopotamia. The book is Passport to the Past: Mesopotamia by Lorna Oakes.Cylinder seals are small cylindrical carved pieces designed to make impressions in clay. They were used in Mesopotamia to sign documents and affix ownership. Kings, officials, and just about anyone with wealth or rank had their own unique seal which they guarded carefully. These seals might be carved of ivory, shell, bone, limestone, or lapis lazuli. According to Oakes, some believe these seals evolved from sheep knuckles used for the same purpose. The book has a picture of a seal with a knob in the shape of a sheep. I could not find a public domain photo of this cylinder, but I did find another cylinder pictured here that has sheep carved into its knob.The sheep knuckle is a small roughly square six-sided bone from the hind legs of the animal. This bone, or analogous bones from deer, antelope, and goats, has been ubiquitous in cultures all over the world. Most commonly it is used for playing games (knuckle bones were the prototype for gaming dice), but it is also used for divination and casting lots. Sheep knuckles have also been carved as amulets and votive offerings. Animal knuckles are often found in burial sites. I don’t know if the sheep knuckle could be used in forensics like fingerprints, but the pictures I’ve seen show considerable variation, so it’s plausible that indentations in clay from a sheep’s knuckle could have been used like a signature. A carved knuckle would have been even more recognizable.I have quite a few books on Mesopotamia but none go into the evolution of cylinder seals. Oakes lists the Metropolitan Museum of Art in New York City and the Oriental Institute of the University of Chicago as sources. If anyone has a written source about the role of sheep bones in the evolution of cylinder seals please let me know.