Just How Tall Were the Dinosaurs?

Everybody knows the dinosaurs were super-tall, but a University of Missouri anatomy professor has just proven everybody wrong. The dinosaurs weren't just super-tall. They were super-duper tall.

The extra height, Casey Holliday and his team of researchers discovered, came from cartilage between the dinosaur's bones. The layers of cartilage, which decomposed from dinosaur skeletons long ago, were much thicker than anybody had previously thought, and may have increased a dinosaur's height by as much as ten percent.

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The pink skeleton is our old view of dinosaurs. The black skeleton is the new, improved version; the blue represents the extra cartilage.

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Holliday and his co-researcher, Lawrence Witmer, an anatomy professor at Ohio University, studied the skeletons of ostriches and alligators, the closest existing relatives to dinosaurs. They determined that the legs of ostriches and alligators are comprised of between six and ten percent cartilage.

Then they took a long look at dinosaur bones.

"The ends of many dinosaurs' long bones, which include leg bones such as the femur or tibia, are rounded and rough and lack major articulating structures like condyles, which are bony projections," Holliday explains in a press release. "This indicated that very thick cartilages formed these structures, and therefore the joints themselves, and would have added significant height to certain dinosaurs."

Based on bone structure, the researchers determined that cartilage didn't add much extra height to the theropod dinosaurs like Tyrannosaurus, but it made ornthischian and sauropod dinosaurs like Triceratops and Brachiosaurus considerably taller.

Because of the thick layers of cartilage, it's unlikely that dinosaurs ever had arthritis the way humans and other mammals do.

The new findings about dinosaur bones may have other implications, like understanding how -- and how quickly -- the dinosaurs were able to move. Could it be that everything we ever learned about dinosaurs was wrong? Something akin to our discover that Pluto was never actually a planet after all?