Isn't Indus Valley (see Harappan) writing very intricate? Or is this speculation of a prototype for that writing?
"It's a big question as to if we can call what we have found true writing," he told BBC News Online, "but we have found symbols that have similarities to what became Indus script.
"One of our research aims is to find more examples of these ancient symbols and follow them as they changed and became a writing system," he added.
http://news.bbc.co.uk/2/hi/science/nature/334517.stm
more at link...