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World’s Biggest Dinosaurs

World’s Biggest Dinosaurs
It’s somewhat frightening to imagine what it must have been like to wander around the plains of Africa and Argentina 100 million years ago. Whereas today you’d be hard-pressed to encounter a beast any bigger than yourself, back then you’d be running for your life as bus-sized creatures roamed free, some remaining largely peaceful and distant, others full of aggression.

The biggest land-based animal alive today is the African bush elephant, with the largest weighing a measly 13.5 tons and measuring 10.6m (34.8ft) long and 4.2m (13.8ft) high. Argentinosaurus, the current official record-holder for largest dinosaur of them all, would have been at least four times the size. It was a sauropod, dinosaurs of the Jurassic and Cretaceous period that were mostly herbivores and known for being very large.
World’s Biggest Dinosaurs

Indeed, many other types of sauropod would have stood tall above the African bush elephant, as would raptors and pterosaurs. Dinosaurs inhabited the Earth for much longer than any modern animal, from 251 to 65 million years ago, allowing plenty of time for certain species to develop into the giant hulks of flesh we now so revere. The biggest dinosaurs discovered to date have largely been determined to live in the Late Cretaceous period, 99.6-65.5 million years ago, before they faced extinction.
For a long time, though, palaeontologists have wondered why dinosaurs grew to be so large. While impressive, size can also be a hindrance. Not only does a large animal need a much higher rate of metabolism, but it must also develop much stronger bones and skeletal structures to be able to hold itself upright. Many of these gigantic animals were also cumbersome and slow, leaving themselves open to attack from large predators. Why did dinosaurs continue to grow for millions of years, then?
One train of thought is that there was a huge surplus of carbon dioxide in the atmosphere during the age of the dinosaurs. This meant that vegetation flourished, and herbivores such as the sauropods simply had an over-abundance of nourishment available to eat. While somewhat of a burden in terms of manoeuvrability, their size would certainly have helped to some extent when fending off smaller carnivores. This leads to another proposal from palaeontologists, namely that some dinosaurs grew in size over millions of years as a form of self-defence. However, others think that these giant dinosaurs were cold-blooded, which was directly responsible for their size. Indeed, warm-blooded animals simply wouldn’t be able to sustain such mammoth sizes, somewhat backed up by the lack of mammals larger than a few tons today.
Huge cold-blooded sauropods, weighing in at up to 100 tons, would have been almost self-sustainable, as they could store heat throughout the day for the colder nights, maintaining a fairly unchanged body temperature and prolonging their survival.