Found in abundance and on every continent, the #fossils of #ammonites, an extinct, squid-like cephalopod that existed 419-66 million years ago, feature a naturally occurring logarithmic #spiral (like that of the #Nautilus)—as the #creature grew in size, it preserved its original #shape. #photooftheday #science #nature #animals #life #species #extinct 📷: Courtesy of Shutterstock