Scale Size - Monolophosaurus. jiangi

Most people think about T.Rex and Velociraptor in terms of theropods. But this widespread popularity overshadows other dangerous meat-eaters of the Mesozoic world. Meet Monolophosaurus, a distant ancestor to both most of the "savage" killers that would later be known. Monolophosaurus. jiangi, or "Single Crested Lizard" lived during the middle of the Jurassic Period about 160 million years ago.

Unlike most meat-eaters dinosaurs that would later develop, the Monolophosaurus had very bizarre shaped skull, which was broad, heavily built and alined with almost up to 20 serrated teeth on each side. Atop on the skull was a large bony nasal crest. Today scientists have no idea what the crest was used for. However, they were able to study and know the nasal was fragile and hollow, this made impossible for the dinosaur to use this ornament for combat. Much like its modern day descendants, birds. It is most likely possible this human-sized predator used the ornament to attract mates.