Dinosaurs aren’t alive today, which is a huge bummer. But we know a lot about them because we’ve found a lot of their bones. Sometimes those bones give us shocking surprises – like the bone in this photo, found a few weeks ago on a dig in Argentina. Look at your own leg: see the part between your knee and your hip? The bone in there is your femur, the biggest bone in your body. Now look at the photo: that’s the dinosaur’s femur, and it’s even longer than that guy’s whole body! They think this bone belonged to a titanosaur, a type of dinosaur that was 65 feet tall and 130 feet long from head to tail. It probably weighed about 77 tons; by comparison, the very scary Tyrannosaurus Rex weighed just 7 tons. In fact, the titanosaur is now the biggest animal ever known to live. And life would be pretty different today if we still had these giant reptiles running down the street.
Wee ones: Who weighed more, the 7-ton T. Rex or the 77-ton titanosaur?
Little kids: If the guy lying next to the bone is 6 feet tall and the bone is 3 feet longer, how long is that bone? Bonus: If your femur is just 1 foot long, how much longer is the titanosaur’s?
Big kids: If your everyday T. Rex weighed 7 tons and the titanosaur weighed 77 tons, how many T. Rex would you have to stack up to balance one titanosaur on a seesaw? Bonus: If the titanosaur was 130 feet long and 3/10 of that was just his tail, how long was his tail?
Wee ones: The 77-ton titanosaur.
Little kids: 9 feet long. Bonus: 8 feet.
Big kids: 11 T. Rex. Bonus: 39 feet.