It had tiny horns behind its eyes and its arms were a bit longer than those of "T. rex". It may have been an ancestor of "Tyrannosaurus". This bipedal meat-eater lived in marshes by streams in what is now Alberta, Canada, during the Upper Cretaceous period, 76-72 million years ago. It may have preyed upon Triceratops. It was named by D.A. Russell in 1970. The type species is "D. torosus".