(Washington Post) -- Scientists have discovered the fossilized remains of a new long-necked, long-tailed dinosaur that has taken the crown for largest terrestrial animal with a body mass that can be accurately determined.
Measurements of bones from its hind leg and foreleg revealed that the animal was 65 tons, and still growing when it died in the Patagonian hills of Argentina about 77 million years ago.
“To put this in perspective, an African elephant is about five tons, T. rex is eight tons, Diplodocus is 18 tons, and a Boeing 737 is around 50 tons,” said study author and paleontologist Kenneth Lacovara at Drexel University. “And then you have Dreadnoughtus at 65 tons.”
Dreadnoughtus, meaning “fears nothing,” is named after the impervious early 20th century battleships. Although it was a plant-eater, a healthy Dreadnoughtus likely had no real issues with predators due to its intimidating size and muscular, weaponized tail.
Paris (AFP) - A supermassive dinosaur that would have weighed as much as 60 small cars has been found in Argentina, where it likely perished in a bog some 77 million years ago, paleontologists said Thursday.
Dubbed Dreadnoughtus (from "fear nothing" in old English), the long-necked lizard would have measured 26 metres (85 feet) from nose to tail and weighed some 60 tonnes -- about as much as seven Tyrannosaurus rex put together.
And the giant wasn't even fully grown when it got bogged down in a flooded plain, where it died next to a smaller companion, researchers reported in the journal Scientific Reports.
"With a body the size of a house, the weight of a herd of elephants, and a weaponised (nine-metre, muscled) tail, Dreadnoughtus would have feared nothing," study co-author Kenneth Lacovara of Drexel University in Philadelphia said of the mighty beast.
The dinosaur's strength evoked Europe's early 20th-century battleships, the dreadnoughts, "which were huge, thickly clad and virtually impervious," Lacovara said.
The fossilised skeleton is the most complete yet found in the category of super-sized, plant-eating dinosaurs called Titanosaurs -- which makes it the largest land animal for which a weight has been calculated with such a degree of accuracy.
The find comprised over 70 percent of the types of bones in the dinosaur's body -- 45 percent of its total skeleton. There were no skull bones.
Palaeontologists uncovered most of the vertebrae from the lizard's tail, a neck vertebra with a diameter of over one yard (0.9 metres), ribs, toes, a claw, a section of jaw and a tooth, and nearly all the bones from its four limbs, including a humerus (upper arm bone) and a femur (thigh bone) over six feet tall.
The femur and humerus are key to calculating the mass of extinct four-legged animals.
"Because the Dreadnoughtus type specimen includes both these bones, its weight can be estimated with confidence," said a Drexel University statement.
"It is by far the best example we have of any of the most giant creatures to ever walk the planet," added Lacovara, who discovered the skeleton in southern Patagonia in 2005 and oversaw its four-year excavation.