We always think of dinosaurs as being really big, but dinosaurs came in all shapes and sizes. The biggest dinosaur we know about is the Brachiosaurus, who was bigger than a house! The smallest dinosaur we know about is the Compsognathus, who was just a little bit bigger than a chicken and weighed less than a cat. There were even some dinosaurs bigger than the Brachiosaurus, but we don’t have enough information yet to say exactly how big they were. Imagine running into one of those on your way home from school!