T rex is back and Pittsburgh's got him -- or them, actually. The Carnegie Museum of Natural History's expanded and redesigned "Dinosaurs in Their Time" exhibit is finally finished, complete with not one but two tyrannosauruses frozen in confrontation. The opening will be June 15 with extended hours -- 8 a.m. to 8 p.m. -- to accommodate expected crowds. The attraction took three years and $36 million, and is now the nation's third-largest collection of real mounted dinosaurs.