Just Why Were Dinosaurs So Big?

One of the many factors that draws dinosaur lovers to dinosaurs is their sheer size. There is no animal that walks the Earth today that begins to compare to the largest dinosaurs of the late Jurassic period. Just what was it that made these prehistoric creatures grow to such incredible proportions?

Why Were Dinosaurs So Big?: The Biggest of the Dinosaurs

When trying to understand why were dinosaurs so big, it is important to take a look at the biggest dinosaurs there were – the sauropods. The sauropods reached their peak in the late Jurassic period and are believed to have maxed out with the incredible Amphicoelias Fragillimus. Amphicoelias Fragillimus could have reached close to 200 feet long and weighed around 135 short tons!

Why Were Dinosaurs So Big?: How Did Amphicoelias Fragillimus Get So Big?

There are a number of theories under debate for just how dinosaurs like Amphicoelias Fragillimus got to be so gigantic.

Theory #1: Plentiful Vegetation

During the time when dinosaurs thrived the Earth’s atmosphere contained much higher levels of carbon dioxide than they do currently. Increased levels of carbon dioxide results in warmer temperatures and in turn that means incredible amounts of lush vegetation. Just how did mass amounts of food relate to the giant carnivores of the period however? As the gigantic herbivores increased in size, carnivores would also have had to grow in size in order to stand any chance of bringing down prey items as large as the Jurassic herbivores.

Theory #2: The Evolutionary Advantage

Another theory that suggests an explanation for the incredible size of dinosaurs is the theory of self preservation. In order to escape predation certain dinosaur species would have grown to incredible sizes in order to survive. This theory suggests that it is possible for larger sauropods to have continued their genetic lines by simply being too large for carnivores to risk attacking. While this took place for some dinosaurs others would have developed other evolutionary advantages such as the armor of the Ankylosauridae. This theory seems to present a more plausible explanation than theory #1 because it allows for different lineages of dinosaur families to develop different adaptations. This would explain why not all herbivores grew to such amazing proportions.

 Theory #3: Coldblooded Gigantism

Another theory proposed by those researching an answer for those asking “why were dinosaurs so big,” is that dinosaurs coldblooded metabolism allowed for gigantism. This theory gets its credence from the fact that using the research we currently have on warmblooded and coldblooded animals, were the giant dinosaurs warmblooded they would not possibly have been able to reach such incredible sizes. However, using a cold blooded model of metabolism it is possible that the giants of the Jurassic would have been able to warm themselves in the daytime sun and cooled their gigantic bodies slowly overnight, maintaining homeothermy. While this theory does explain how the Jurassic giants could attain such incredible size, it does not jive with current beliefs that certain carnivorous dinosaurs were warmblooded. Despite this fact, some evolutionary biologists and paleontologists believe that it is possible that not all dinosaurs had the same type of metabolism.

So there you have it! A number of theories to answer the burning question – why were dinosaurs so big?