A huge fossil site from the Jurassic era was discovered in Argentina.

Paleontologists said that the site was found four years after it was first discovered in Patagonia, southern Argentina, AFP reported (via Yahoo! News) from the journal Ameghiniana. The site measures 23,000 square miles (60,000 square kilometers) and is situated along the Deseado Massif mountain range.

Garcia Massini, who is heading the research team studying the fossil site, said that the fossils are between 140 and 160 million years old, the news outlet added. Erosion recently exposed the fossils, causing them to lie on the surface.

According to researchers, the fossils are well preserved and that each rock removed from the location could likely lead to more discoveries, AFP further reported. The fossils are preserved almost instantly, some in less than a day.

"No other place in the world contains the same amount and diversity of Jurassic fossils," said geologist Juan Garcia Massini from the Regional Center for Scientific Research and Technology Transfer, or, CRILAR, as quoted by AFP. "You can see the landscape as it appeared in the Jurassic -- how thermal waters, lakes and streams as well as plants and other parts of the ecosystem were distributed."

According to Ignacio Escapa of the Egidio Feruglio Paleontology Museum, researchers discovered "a wide range of micro and macro-organisms," AFP noted. Garcia Massini said the site offers a look at how fungi, cyanobacteria and worms moved when they were still active.

Did Huge Dinosaurs Swim?

Researchers now believe that giant sauropod dinosaurs knew how to swim when they were still alive.

Lida Xing, a paleontologist at China University of Geosciences, and colleagues published an article about the issue in Scientific Reports.

According to Forbes, the largest sauropods' weight of 70 tons likely made it hard for them to walk on land. In the early 20th century, this led some researchers to believe that sauropods spent the majority of their time swimming instead of walking.

Evidence obtained from hand-only trackaways showed that only the sauropods' front or hind feet were imprinted into the sediment, The Conversation reported. Researchers argued that the sauropods were swimming with their body staying buoyant in deep water while only one set of their limbs were reaching the bottom.

"Nobody would say these huge dinosaurs could stagger along on their hind legs alone -- they would fall over," said Xing, as quoted by Forbes.

The new trackways were seen in Gansu Province in northern China, The Conversation noted. The tracks originated from the Lower Cretaceous era over 120 million years ago.