Giant Dinosaurs Lived on Earth Much Earlier Than Previously Thought

Rodiano Bonacci
Luglio 12, 2018

Recently-unearthed fossils in Argentina suggest that giant dinosaurs roamed the Earth some 30 million years earlier than scientists had previously thought.

The remains included shoulder blades, cervical vertebrae and bones from the forelimbs, feet and skull of the four dinosaurs.

The earlier understanding of dinosaur existence was said to be 180 million years ago, which this discovery dismisses.

The newly identified bus-size beast - named Ingentia prima, which means "first giant" in Latin - weighed up to 11 tons (10 metric tons) and measured up to 32 feet (10 meters) long. That is 205 million years ago.

"This reveals that the first pulse towards gigantism in dinosaurs occurred over 30 million years before the appearance of the first [true sauropods]", write the researchers in their study. But the lessemsaurids tell us that at least some dinosaurs were able to attain giant sizes during the latest part of the Triassic, before the extinction.

As the researchers pointed out, during early-Triassic, when dinosaurs started to grow, there were many small reptiles which evolved in giant dinosaurs.

The plant eater, described in Nature Ecology & Evolution, is an ancestor of its famously freakish titanosaur cousins Brachiosaurus and Diplodocus, renowned for their enormous necks and tails.

The researchers found that the weight of I. prima ranged between seven and 10 tons, and showed elongated neck and long tail albeit not as pronounced as those seen in their later relatives.

They had nostrils high up on their skulls - rather than being located at the end of the snout like those of so many other terrestrial vertebrates.

For most dinosaurs, gigantism proved to be an evolutionary survival tool, especially among herbivores who could use their size as a form of defence against predators.

Explained Dr Apaldetti: "This respiratory system is related to the development of air sacs inside their bodies - like modern birds".

'It allowed them to have large reserves of oxygenated air, and also helped them to keep cool despite being so big.

On the other hand, traces of blood vessels in these bones indicate that these lizards grow up "jerks", which was not typical for later sauropods and all the other dinosaurs didn't go on straight legs, and squatting.

Find, Baldetti and her colleagues belong to the number of sauropods - large quadrupedal herbivorous dinosaurs, making rate of its huge mass, a huge number of eggs in the clutch and rapid growth of young animals.

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