Paleontologists in Portugal have unearthed the fossilized skeleton of what could be the largest dinosaur ever found in Europe.

The remains are thought to be those of a sauropod, a herbivorous dinosaur 12 meters (39 feet) tall and 25 meters long that roamed the Earth around 150 million years ago.

"It's one of the biggest specimens discovered in Europe, perhaps in the world," paleontologist Elisabete Malafaia, from the Faculty of Sciences at Lisbon University, told AFP on Monday.

The bones were uncovered by Portuguese and Spanish scientists in the garden of a house near Pombal in central Portugal at the beginning of August.

Three people inspect a sauropod fossil at an excavation site.
The dinosaur fossil. (Instituto Dom Luiz, Faculdade de Ciências da Universidade de Lisboa/AFP)

Among the bones collected, they found the remains of a rib about three meters long, Malafaia said.

Fossil fragments were first noticed at the site in 2017, when the owner was digging up his garden to make way for an extension.

He contacted paleontologists, who unearthed part of the dinosaur skeleton earlier this month and have been examining it ever since.

Huge Dinosaur Fossil In Portugal
The team with the fossil. (Instituto Dom Luiz/Faculty of Sciences of the University of Lisbon)

Sauropods have characteristically long necks and tails and are among the largest animals to have ever lived.

The fossils discovered at the Monte Agudo site in Pombal are thought to be those of a brachiosaurid who lived during the Upper Jurassic period.

The fact that the vertebrae and ribs were found at the same location and in the position they would have been in the dinosaur's anatomy is "relatively rare", Malafaia said.

The team may conduct more digs in the coming months at the site and in the surrounding area.

© Agence France-Presse