Paleontologists have discovered the remains of two new species of herbivorous dinosaurs that roamed Argentina’s southern El Calafate area 70 million years ago.
Dubbed the “Nullotitan Glaciaris,” the first dinosaur measured 82 feet in length, and had four legs and a long neck, according to reps for the natural sciences museum of Buenos Aires, Museo Argentino de Ciencias Naturales Bernardino Rivadavia.
Remains of the “Isasicursor Santacrucensis” were also unearthed during the dig. This second species measured 13 feet long and could move rapidly on its hinds legs.
“These [discoveries] are from a new archaeological site that is full of plant fossils, dinosaur fossils and other vertebrae,” paleontologist Fernando Novas told Reuters. “It reveals to us an ecosystem from around 70 million years ago — before dinosaurs became extinct.”
Novas declared the Nullotitan “one of the last great dinosaurs, the last giants that lived on the earth.” He said the species must have been a common animal because of the large quantity of its bones excavated during the dig.
The discovery of the Isasicursor Santacrucensis is especially notable, Novas said, because it proves the existence of prehistoric pack animals.
“We found many bones from this animal but of different sizes, adults and youth, all mixed together,” Novas said. “This is one of the few discoveries that reveal to us that these dinosaurs species lived in groups, in packs. They formed packs as a defense mechanism against predators, that in the past were giant carnivores related to Tyrannosaurus rex.”