Contender found for largest dinosaur
The discovery of the 122-foot-long Patagotitan mayorum is helping scientists piece together the lineage of long-necked, plant-eating titanosaurs
Weighing nearly 70 tons, heavier than 10 adult African elephants, the dinosaur was the largest creature to ever walk on Earth, according to some scientists.
The plant-eating animal first made headlines in 2014, after a rancher from the Patagonia region in Argentina discovered a fossil bone. Last year, the American Museum of Natural History in New York added a cast of the 122-foot-long creature to its exhibit. Its neck and head are so long that they extend outside the gallery.
Despite its fame, the dinosaur did not have an official scientific name — until now.
A report published last week in the journal Proceedings of the Royal Society B calls it Patagotitan mayorum. “Patagotitan” can be interpreted as “giant from Patagonia,” and “mayorum” is a tribute to the rancher family that hosted a team of paleontologists, geologists, students and volunteers as they excavated dozens of fossils from the area.
More than 150 Patagotitan fossils have been unearthed there over the past few years. Finding a significant number of fossils belonging to the same species is not rare — except for such a big animal, dinosaur specialist José Luis Carballido said in an email.
“It’s a real paleontological treasure,” Carballido notes on the museum's website. “There were lots of fossils in great preservation, practically intact, something that does not happen often.”
These discoveries have allowed scientists to create the most complete anatomic reconstruction of any large terrestrial herbivore in the planet’s history, according to the Egidio Feruglio paleontology museum in Trelew, Argentina.
Patagotitan mayorum, which lived about 100 million years ago during the late Cretaceous Period, is considered a titanosaur, a diverse lineage of plant-eating, long-necked dinosaurs with long tails that walked on four legs.
Titanosaurs varied greatly in size, with the smallest species weighing as much as an adult elephant and the largest ones weighing in at more than 60 tons. The fossil find in Argentina gave scientists a clearer picture of how titanosaurs evolved in terms of their body mass, with the research revealing that most of the giant titanosaurs discovered there belonged to a single lineage, according to the museum.
“This means that the evolution of extreme gigantism within titanosaurs happened but only once and not in multiple separate events,” Diego Pol, one of the authors of the report, said in a statement. “We can see some other cases of size increase relative to the ancestral size of titanosaurs, but none of them was as dramatic as the one seen in this group and exemplified by Patagotitan.”
The creature’s most important contribution to science, Carballido said, is the amount of information it gave to researchers.
Scientists have found fossils of other giant dinosaurs in the titanosaur lineage such as Argentinosaurus and Puertasaurus in the Argentine desert. But scientists had to rely on a limited number of bones to get a sense of their weight and size, Carballido said.
With the Patagotitan, however, scientists were able to find a humerus (arm bone) and femur (thigh bone), he said.
Some scientists remain cautious about proclaiming it the biggest of them all.
Mathew Wedel, a paleontologist at the Western University of Health Sciences in California, told Smithsonian Magazine that it is more likely that Patagotitan is comparable in size to Argentinosaurus, the previous record holder.
“I think it would be more accurate to say that Argentinosaurus, Puertasaurus and Patagotitan are so similar in size that it is impossible for now to say which one was the largest,” Wedel said.
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A reconstructed Patagotitan mayorum, a 70-ton titanosaur discovered in the Patagonia region of Argentina. Some scientists believe that it was the largest dinosaur that walked the Earth.