From a secular scientist:
“From my reading of the fossil record of dinosaurs, no direct ancestors have been discovered for any dinosaur species. Alas, my list of dinosaurian ancestors is an empty one.”
Source: E-mail interview (for clarification purposes) with Dr. David Weishampel, Anatomist and Paleontologist, Johns Hopkins University and Lead Editor of the encyclopedic reference book The Dinosauria, conducted December 6, 2005, by author. (Werner, Dr. Carl. Evolution: The Grand Experiment (3rd Edition) . New Leaf Press. Kindle Edition.)