‘Evolution of hugeness’: Massive dinosaurs appeared more than once in earth’s history

[T]he remains of an unusually-large-for-its-time dinosaur found in Argentina provides new insight into the evolution of hugeness—and suggest that the way dinos like Brontosaurus got large wasn’t the only way to do it.

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In Nature Ecology & Evolution, Universidad Nacional de San Juan paleontologist Cecilia Apaldetti of the Universidad Nacional de San Juan, [Diego] Abelín and colleagues named the animal Ingentia prima.

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Assuming normal sauropodomorph proportions, Apaldetti estimates that the living animal would have been between 26 and 33 feet long and weigh around 10 tons, or as much as two or three African elephants. In Triassic terms, this is enormous. “Ingentia exceeds three times the size of the largest Triassic dinosaurs known to date,” Apaldetti says.

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“The appearance of animals of slightly larger body size appearing much earlier is really interesting,” [paleontologist Jonah] Choiniere says—particularly because increasing dinosaur body size and different shapes occurred prior to the end-Triassic mass extinction that was thought to finally give dinosaurs a competitive edge. So now we know that sauropodomorphs grew to giant sizes at least twice.

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For now, the discovery of Ingentia adds to the deep significance of the Triassic. This was not only the time of the first giant dinosaurs, dome-headed weirdos and vacuum-faced oddities, but also when the ancestors of animals alive today—birds, crocodiles, mammals—flourished.

Read full, original post: The Most Massive of Dinos Evolved Earlier Than Previously Thought