Homocephalosaurus

A Homocephalosaurus (name meaning "human-headed reptile") is an extinct medium-sized omnivorous pachycephalosaurid non-avian dinosaur that lived in what is now Eurasia and North America during the Late Cretaceous and Middle Paleocene (71.2-57.6 million years ago). They were bipedal like all known Pachycephalosaurids and were omnivorous like all later Pachycephalosaurids, feeding on wide variety of species of plants, fungi, and animals, sharing the same diet as humans today. They were about the size of an emu and about as long as an American alligator while its fossilized vocql structures confirmed that Homocephalosaurus was likely able to speak in languages similar to modern humans. They had an enlarged skull housing a very large brain, even more so than their relatives such as Pachycephalosaurus, Stegoceras, or even Prenocephale, which were probably also about as smart as early humans and made stone tools for hunting larger animals, and the brain size of Homocephalosaurus suggests that they were about as smart as modern-styled humans (Homo Sapiens) and just as creative, which would explain why there are preserved toys, stone tools, robots, vehicles, and other inventions found in the Cretaceous and early Paleocene. They most likely had built their own "villages" and even "cities" similar to today's man-made cities, as some fossilized building tools and structures of buildings dated from the Cretaceous to the Paleocene suggests. It is unknown on why Homocephalosaurus became extinct in the Early Paleocene even if it survived the K-T mass extinction (when the extinction killed off its more primitive relatives like Pachycephalosaurus, Stegoceras, etc), but it may have been due to newly evolved mammal predators, climate change during the Paleocene, diseases, or the fact that they couldn't make spacecraft, which would have allowed them to escape their extinction during that time.

Revival
Despite their extinction, they were brought back from extinction, so they are now tolerant to diseases, climate change, etc, and they now live in peace with all dylanusids and sapient species/beings, except vampires.