A newly discovered titanosaur from Argentina has been recognised as the largest dinosaur found to date. Patagotitan mayorum weighed approximately 69 tonnes and measured 37 metres in length, almost as long as a Boeing 737 aircraft. With its neck raised, it could reach a height of up to 15 metres.

In 2013, four years before this article was published, an Argentine shepherd named Aureliano Hernandez discovered a fossilised bone protruding from rock on the farm where he worked. Many giant dinosaurs have been found in Argentina, so the farm’s owners, the Mayo family, contacted local palaeontologists to begin excavations. Unfortunately, Hernandez did not live to see the discovery of what would become the largest dinosaur found to date, the titanosaur Patagotitan mayorum.

The excavation uncovered the remains of at least six titanosaurs. The bone found by Hernandez proved to be a femur measuring 2.4 metres in length. Over 18 months, palaeontologists excavated the bones and reconstructed the giant’s skeleton, with an estimated length of 37 metres, making it the largest dinosaur found to date.

The remains of the six dinosaurs were recovered from three rock layers representing different time intervals. Researchers therefore suggest that a lake occupied the site and that titanosaurs returned to drink there over several generations. According to Luis Carballido of Argentina’s National Scientific and Technical Research Council (CONICET), this indicates site fidelity, a behaviour not previously documented in animals of this size. The lake may eventually have dried up, and thirst may have contributed to the deaths of the six titanosaurs.

Patagotitan mayorum – named after Patagonia, where it was found, and the Mayo family, who permitted excavation on their land – lived during the Cretaceous, between 113 and 83 million years ago. Although the six recovered dinosaurs were enormous, analysis of their bones indicated that they had not yet finished growing. Even larger individuals may therefore remain to be discovered in Argentina.

Titanosaurs were the largest animals ever to inhabit Earth in terms of dimensions, although not mass, for which the living blue whale holds the record. Until this discovery, the leading contender was Argentinosaurus huinculensis, also found in Patagonia, but it has now been surpassed by the newly described Patagotitan.

The American Museum of Natural History in New York City currently displays a replica of the skeleton of Patagotitan mayorum, which is too large to fit within a single gallery. Opinions differ on whether an even larger titanosaur might be discovered. The possibility remains open, although this may be the largest specimen ever found.

Sources: LiveScience, The Atlantic