Dino bones reveal T.Rex’s awkward teen phase

We can’t observe dinosaur behavior, so scientists turn to the traces we have left — fossils, footprints, a sprinkle of DNA — to understand how these giant animals lived.

Studying how quickly a dinosaur grew can tell us something about their behavior — for instance, did they need to get big quickly to help them hunt?

Sometimes currently living animals can help us understand the past, but this is tricky with dinosaurs because they’re related to both birds and reptiles.

And birds and reptiles today grow quite differently.

Birds tend to have one big growth spurt and reach their adult size quickly.

Reptiles, on the other hand, tend to grow more slowly, and body size can vary widely between adults and juveniles.

Bones are kind of like trees. Each period of growth creates a marking in the bone, like a tree ring does a tree.

Blood vessels in the bone can reveal growth rate as well — more organized blood vessels means that growth rate was slow, and vice versa.

Carefully slicing open T.rex bones and analyzing them under a microscope revealed T.rex went through a huge growth spurt early in life — possibly to help them hunt.

Further studies will help scientist understand why each dinosaur grew the way they did. For instance, it is possible T.rex grew fast to keep up with its quickly-growing prey.