With some sauropods reaching lengths of an astonishing 40 meters (131 feet) long, they were the true giants of the dinosaur age. But most have wondered, at some point or another, just how they were able to keep their long, slender necks up without breaking? It seems that the answer may lie in the way their backbones fit together.
When people first started digging up sauropods 150 years or so ago, there was much debate over how sauropods looked. Many early representations placed the dinosaurs in swamps with their heads floating above the surface, as people didn’t believe such large animals could live on land. Even the infamous Dippy the dinosaur, who once graced the Hintze Hall of the Natural History Museum, London, had his head pointing downwards until the 1960s and his tail dragging along the floor until as late as 1993.
But a new study, to be published in the journal Ameghiniana, suggests that the unique way in which the dinosaur's vertebrae fit together may help explain the impressive strength in its super-sized back. When vertebrae grow, they start as two separate pieces – the neural arch and the centrum – which eventually fuse together, encasing the spinal column in bone.
The researchers claim that the special “zigzag” or “toothed” connection between the neural arch and the centrum on each vertebra increases the surface area, making them incredibly resistant to stress and increasing the weight they could take before they’d break. This is in stark contrast to mammals, for example, in which the two sections are joined together by a flat surface.
This interesting discovery may be yet another adaptation the enormous beasts had that allowed them to grow such extraordinary necks. Their large size actually helped enable them to grow elongated necks, as together with their large pillar-like legs, it gave them an incredibly stable base from which to support their neck. The dinoasaur's head was also reduced massively in size and weight, sacrificing its ability to process food.
The necks themselves were also adapted, mainly to try and reduce weight so that less effort was needed to support them. While the dinosaurs may have had an impressive 19 cervical vertebrae (compared to almost all mammals that only have seven), roughly 60 percent of the bones were actually made up of air. These huge air pockets significantly reduced the weight of the bone.
So while the long-necked behemoths may seem ungainly and hardly possible, the gentle giants clearly had a whole suite of adaptations that allowed for them to successfully inhabit every corner of the world.