New Giant Dinosaur Discovered That Rewrites Evolutionary History

Mindy Sparks
July 11, 2018

The researchers say the Ingentia prima, which loosely translates to "first giant", was a four-legged herbivore that grew cyclically, meaning it would grow quickly for stretches of time and then stop growing for similar stretches, kind of like a tree.

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

"As soon as we found it, we realized it was something different".

'But with this discovery we can see the first steps toward gigantism occurred 30 million years before the giants dominated practically the entire planet'.

Analysis showed that I. prima weighed between seven and 10 tonnes (the largest African elephants weight between six and seven tonnes), and it already exhibited an elongated neck and long tail, though not almost as pronounced as those seen later.

"Although the origin of gigantism in sauropodomorphs [sauropods] was a pivotal stage in the history of dinosaurs, an incomplete fossil record obscures details of this crucial evolutionary change", the authors wrote in the study.

Like later sauropods, lessemsaurids had elongated necks and tails, as well as air sacs resembling those that are found in birds.

Dr Apaldetti said: 'Gigantism is an evolutionary survival strategy, especially for herbivorous animals'.

The team has been studying the Triassic period, when dinosaurs were just beginning to appear.

Cecilia Apaldetti of the University of San Juan said, 'Before this discovery, gigantism was considered to have emerged during the Jurassic period, approximately 180 million years ago, but Ingentia prima lived at the end of the Triassic, between 210 and 205 million years ago'.

Cyclic growth was common among dinosaurs of that era, but no other known species exceeded more than three metres in length and 1.8 tonnes in weight. The bones discovered by the team displayed cyclical and seasonal growth, and it is believed that the species grew to 26-33 feet tall and weighed equal to two or three African elephants.

These adaptations included such things as small skulls, long necks and tails, column-like legs, rapid bone growth, and pneumatic vertebrae, where air spaces exist within the bones to make them light (a trait that still exists in modern birds).

The Balde de Leyes site, which spans several thousand acres, was first discovered in 2001 and has produced hundreds of specimens.

Other reports by Iphone Fresh

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