Monday, 20 August, 2018

Giant Dinosaurs Lived on Earth Much Earlier Than Previously Thought

Huge gentle giant dinosaur the size of a double decker bus discovered in Argentina An illustration of the herbivorous monster dinosaur
Theresa Hayes | 12 July, 2018, 22:09

The bones of the Ingentia prima were found in western Argentina, in Balde de Leyes, an area where other dinosaur species and ancestors of turtles, iguanas, and mice were found.

"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. However, Ingentia prima inhabited the Earth in the late Triassic period, somewhere between 210 and 205 million years ago.

For the new study, lead scientist Cecilia Apaldetti and her team from the National University of San Juan analysed the fossil, along with three new specimens of a closely related and previously documented dinosaur known as Lessemsaurus sauropoides (which was done for comparison).

The fossil was discovered from the northwest of Argentina during a field trip.

Not only is the discovery important because it becomes the oldest registered dinosaur, but hints at how sauropods - the dinosaur breed with a long neck, long tail, small heads, and four thick, pillar-like legs - got so big.

The dramatic discovery winds back the clock on the emergence of giant dinosaurs by a staggering 30 million years - shedding fresh light on their evolution.

An improved respiratory system and modifications to the vertebral musculature and hind limbs were key factors to the giant growth spurt, theorize the researchers.

The dinosaur had an elongated neck and tail, although not on the scale of Diplodocus.

Sauropods are the largest known creatures to ever walk on land but these massive dinosaurs did not emerge with their bodies already bulked up. "It was at least twice as large as the other herbivores of the time".

The creature has been dubbed "Ingentia prima" (Latin for "first giant"), and it's been classed as a sauropodomorph, the group that would later evolve into the big sauropods. Called the Ingenia prima, this dinosaur was thrice the dimensions of the bulkiest of Triassic dinosaurs.

But unlike their more recent counterparts they stood on bent legs and had bones that grew thick through accelerated bursts.

These similarities, in particular, showed that the bones of these dinosaurs present the same "air bags" that helped them to cool themselves and maintain your body, which paleontologists find the remains of the Diplodocus and argentinosaurus.

The last, iconic sauropods had the benefit of a long history of evolutionary innovation in this regard, said Dr Apaldetti.