The answer depends on what you mean by “the most dangerous.” If you’re asking which dinosaur would have posed the greatest threat to a human, many paleontologists and science communicators point to large, agile theropods—especially tyrannosaurids like Tyrannosaurus rex or close relatives such as Giganotosaurus or Utahraptor—for their combination of size, bite force, and hunting abilities. However, there isn’t a single definitive “most dangerous” dino; different sources rank contenders differently based on traits like bite power, speed, pack behavior, and maneuverability. Key contenders often highlighted

• Tyrannosaurus rex: Noted for an enormous bite force, robust jaws, and a role as apex predator in its ecosystem. Many lists place T. rex at or near the top for sheer predatory capability. [web results vary by source]
• Utahraptor: A large, fast, and highly capable predator with a formidable claw; often cited as especially dangerous to humans if encountered in the wild. [web results vary by source]
• Spinosaurus: Among the largest known carnivorous dinosaurs, with adaptations suggesting a powerful predatory strategy, though its hunting in aquatic settings adds complexity to its danger profile. [web results vary by source]
• Allosaurus and Mapusaurus: Large theropods known for powerful jaws and packs in some interpretations, contributing to perceptions of high danger. [web results vary by source]
• Majungasaurus and certain other theropods: Frequently highlighted in popular media for fierce predation styles, sometimes cited as particularly lethal in their contexts. [web results vary by source]

Important caveats

• Most discussions about “danger to humans” are hypothetical, since humans did not share ecosystems with these dinosaurs. Interpretations depend on anatomical features (bite force, claws, speed), behavior (solitary vs. pack hunting), and ecological niche.
• Popular lists often mix scientific assessments with storytelling and ranking by experts or media personalities. There is no universally agreed single “most dangerous” dinosaur. [web results vary by source]

If you’d like, I can gather and compare specific expert lists and their rankings to give you a more precise, sourced answer.