This 16 September 2018 video says about itself:
The Biggest Dinosaurs Of All Time
Some dinosaurs were the biggest land-dwelling animals to ever exist on Earth. When you picture a dinosaur, you might imagine a 13-meter long T. rex or a Titanosaur the size of an airplane.
But the first dinosaurs would have only come up to your knee. It turns out that sauropods, like Brontosaurus, developed special adaptations that allowed them to tower over the competition.