Categories Dinosaurs The History of Paleontology Pachycephalosaurus Invalid??? The Return of Tylosteus ornatus Post author By maxsblogosaurus Post date April 1, 2026 No Comments on Pachycephalosaurus Invalid??? The Return of Tylosteus ornatus All hail the dome-headed…Tylosteids? Tags April Fools, Dinosaurs, Joseph Leidy, Pachycephalosaurids, Pachycephalosaurs, Pachycephalosaurus, Pachycephalosaurus grangeri, Pachycephalosaurus wyomingensis, Paleontology, Tylosteus, Tylosteus ornatus