For decades, archaeologists have pored over the spectacular images of stampeding horses and charging bison left by Ice Age artists on European cave walls more than 10,000 years ago. But few researchers have paid much attention to the simple geometric signs that often accompany the art. Unable to interpret or decipher these markings, many archaeologists dismissed them as mere decorations. Read more at National Geographic News
Image from the Quarterly Journal of Science, 1864. courtesy of Wikimedia Commons.