www.bbc.com ＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊＊ www.bbc.com Tyrannosaurus rex skull unearthed in South Dakota to be auctioned in New York A Tyrannosaurus rex skull found in South Dakota is expected to sell for at least $15 million (Y2 bil…