Their long necks, huge bodies, small heads, and flared tails make sauropods one of the most famous dinosaurs ever discovered. These plant-eating giants include some of the largest land animals in Earth’s history, with some species reaching nearly 130 feet (40 meters) in length. Famous examples include Diplodocus and Brachiosaurus.
Now, researchers studying fossils from southern Argentina have identified a new member of this iconic group. dinosaurs named Vicaracosaurus dionydeiwas smaller than the largest sauropods, but still had an estimated length of 65 feet (20 meters).
Giant dinosaur fossil discovered in Patagonia
Scientists recovered part of the dinosaur’s spine, including more than 30 vertebrae from its neck, back and tail, as well as several ribs and part of its pelvis. The bone structure revealed that the remains belonged to an adult animal that lived on the ancient southern supercontinent Gondwana some 155 million years ago.
What makes this fossil particularly interesting is its unusual combination of features. Part of the skeleton closely resembles that of Giraffatitan, a brachiosaur dinosaur discovered in Tanzania. Other traits, particularly those of the dorsal vertebrae, are very similar to North American diplodocus and related species.
“Phylogenetic analysis of the skeleton shows that: Vicaracosaurus dionydei “This fossil is related to the Brachiosauridae and would be the first Brachiosauridae to have lived during the Jurassic period of South America,” said LMU PhD student Alexandra Reuter, lead author of the study. The paleontologist examined the fossil as part of his doctoral research.
New clues about Jurassic dinosaur evolution
The discovery could help scientists better understand how giant sauropods evolved in the Southern Hemisphere during the Late Jurassic Period.
“Our knowledge of the evolution of sauropods during the Late Jurassic has so far been almost entirely based on numerous fossil discoveries made in North America and other parts of the northern hemisphere. For a long time, there was only one significant site on the southern continent, in Tanzania: the fossil site of Chubut province in Argentina, the origin of Bicharacosaurus dionidei. “provides important comparative material and allows us to continually supplement and reassess our understanding, contributing to the elucidation of the evolutionary history of these animals, especially in the Southern Hemisphere,” says study leader Professor Oliver Raucht, dinosaur expert at the Bavarian State Collection of Natural History (SNSB).
Dinosaur named after local shepherd
first fossil Vicaracosaurus dionydei Found on his farm by shepherd Dionid Mesa. Researchers honored him by using his name in the species designation. The genus name comes from the colloquial Spanish word “bicharraco,” meaning “big animal.”
The fossil was discovered in the Canadon-Carcareo rock formation in the Chubut province of Patagonia. The remains are currently stored at the Egidio Ferrio Museum of Paleontology in Trelew, Argentina.

