Dinosaurs: Full Of Air?

Photo by Fausto García on Unsplash

Right now, giraffes are the tallest animals on Earth. Growing to a height of up to 6m, they're huge, right!? Now, imagine 3 giraffes all stood on top of eachother. Seems silly but that's the estimated height of the tallest dinosaur – Sauroposeidon [1].

Animals of this size haven't roamed the Earth since the extinction of the sauropod dinosaurs ~145 million years ago, not even the more recently extinct megafauna were so big. Now, why is that? What made the dinosaurs so special that they were able to grow so large?

One suggestion as to how these creatures managed to tower over others is that they were, well, full of air. Okay, maybe not quite ‘full’, but the fossilised bones of various dinosaur species have shown evidence of pneumatisation (the presence of air). Sauropods especially have been found to have had a large number of air sacs in their vertebra. What does this have to do with height? Well, the presence of air sacs in their bones led to these animals weighing significantly less than any solid-boned counterparts would have, meaning their legs were able to support a much bigger body. These pneumatised bones may have also increased the respiratory capacity of dinosaurs, and given them an advantage when it came to regulating their body heat [2].

Another theory as to how dinosaurs got so big is that it has something to do with their teeth, or more specifically the lack of a certain type of teeth [3]. This brought with it two possible advantages – their heads could stay small and therefore be supported by such a long neck, and they weren’t able to chew their food. The latter may seem like a disadvantage, but it’s the opposite. Instead of chewing, they ripped vegetation which was then simply swallowed whole and broken down in their stomach. There’s also evidence that, like chickens, some dinosaurs swallowed stones which aided in grinding food once it reached the digestive system. This allowed these dinosaurs to consume large amounts of food/nutrients in a shorter amount of time, helping them to maintain such a large body size.

Maybe they’re not just full of air after all?

It’s important to remember that, when it comes to dinosaurs, a lot of facts remain unknown to us, and may always be out of reach due to the constrictions of what fossils can/cannot teach us. So the above information is often disputed in the scientific community, and theories will change as research progresses.

Emily

1 Wedel, M. J., Cifelli, R. L., KENT SANDERS Wedel, R., Wedel sauropod, M. J. and Cifelli rlc, R. L. Osteology, paleobiology, and relationships of the sauropod dinosaur Sauroposeidon.

2 Vertebral Pneumaticity, Air Sacs, and the Physiology of Sauropod Dinosaurs on JSTOR.

3 Sander, P. M. and Clauss, M. (2008, October 10) Paleontology: Sauropod gigantism. Science (80-. )., American Association for the Advancement of Science.

All views my own. All information correct at time of publishing.