The title of the "World's Largest Dinosaur" is often attributed to the Argentinosaurus, a massive sauropod that lived during the Late Cretaceous period, around 94 to 97 million years ago. Estimates suggest that it could have reached lengths of up to 100 feet and weighed as much as 100 tons. Its long neck and tail allowed it to reach high vegetation, making it an efficient herbivore. Another contender for the title is the Patagotitan, discovered in Argentina in 2014. This dinosaur is believed to have been similar in size to the Argentinosaurus, with some estimates suggesting it could have weighed even more. Both dinosaurs are examples of the incredible diversity and size of prehistoric life on Earth.