How Big Could They Grow

Article | Updated 10 years ago

The largest theropod dinosaurs are estimated to have a maximum body size of around 12–13 metres.

Almost all fossil dinosaur skeletons are incomplete so their size is estimated by extrapolating from the bones that are found. Torvosaurus is arguably one of the largest Jurassic theropods. Its skull was estimated to be over 1.5 metres long based on a very large jaw bone found in 150-million-year-old rocks from Portugal. This skull is similar in size to the largest carcharodontosaur skull from the mid-Cretaceous and the largest tyrannosaur skull from the Late Cretaceous. A theropod skull of 1.5 metres corresponds to a body length of roughly 12–13 metres.

Limits to growth

When a body doubles in size, it becomes eight times heavier but its muscles and bones are only four times stronger. The only way to compensate for this effect is to increase the relative thickness of the bones and the muscles, which would make the theropod even heavier and place additional strain on the lungs and heart. So it seems that growing to about 12–13 metres is about the limit for these dinosaurs.