Patagonia is one of the richest places in the world in dinosaurs fossils. Some of the most spectacular species of these legendary animals have been discovered in several paleontology sites spread around its vast spaces.

 

Dinosaurs dominated the Earth from the Triassic, 230 million years ago, until their extinction by the end of the Triassic, 65 million years ago. From their origin they split into two big lineages: Ornitschia and Saurischia, according to the different shape of their hip and pelvis. In South America, most of the findings are from the Saurischia order.

 

During the Mesozoic Patagonia was part of the Gondwana super-continent, composed of the actual South America, Africa, Antarctica and Australia. The climate then was much more warm and humid than now, with big and thick forests where we now see steppes and deserts. The Andes mountain range had not appeared yet; its formation put and obstacle to the humid winds coming from the Pacific Ocean, producing dryness and erosion, which together with the human activities have gradually taken a big amount of fossils into the light.

 

 

The first dinosaurs discovered in Patagonia date back to 1882, when Buratovich, a major of the Argentinian Army found some bones near the confluence of rivers Limay and Neuquén. Those were sent to the scientific and paleontologist Florentino Ameghino, who financed several expeditions to explore the Patagonian territory. Later, in 1919, the German Fiedrich von Heune, the most prominent European paleontologist of its time, conducted several studies of the Cretaceous in Patagonia.

 

More recently the paleontologist José Bonaparte has dedicated his professional life to study the Mesozoic vertebrates in the Southern hemisphere, highlighting their differences with the ones in the Northern hemisphere coming from the super-continent Laurasia. Among those differences the most significant one at first sight is the bigger size generally developed by the southern species. The works of Bonaparte are today continued by some of his most prominent disciples, like Rodolfo Coria, Fernando Novas, Leonardo Salgado y Sebastián Apesteguía.

 

The Neuquén province gathers some of the most significant paleontology findings in Patagonia: in particular the Limay formation, near the town of Plaza Huincul and El Chocón areas stand out. The remains of Argentinosaurus huinculensis, the largest dinosaur found yet, with an estimated size of 35 to 45 m. was found in “Estancia Las Overas” in Plaza Huincul. Argentinosaurus belongs to the Sauropoda infra-order, a group of herbivore quadrupedal dinosaurs of gregarious habits, characterized by their huge proportions, long neck and tail, small head and robust legs.

 

 

The remains of the Argentinosaurus huinculensis are exhibited in the Carmen Funes Musuem, in Plaza Huincul, where there is also a copy of the skeleton of Caypullisaurus bonapartei, the most complete ichthyosaur found in South America, which was discovered in the Vaca Muerta (Dead Cow) formation in Neuquén. Also in this museum, you can see samples of the major finding of dinosaur eggs in the world, the one discovered in Auca Mahuida. The eggs found contained remains of skin and bones of the embryos, and thanks to this finding the scientists could see for the first time the skull of a sauropod embryo and feel the rugosity of their skin.

 

In the sites of the area of Villa El Chocón, in 1993, fossils of Giganotosaurus carolinii were found. This is considered the largest carnivore dinosaur found yet, surpassing the famous Tyranosaurus rex. Giganotosaurus belongs to the Theropoda group, a suborder of biped and carnivore dinosaurs that were the dominant terrestrial predators during their time. Some advanced theropods developed feathers, and their direct descendants are the actual birds. The Ernesto Bachmann Municipal Museum in Villa El Chocón exhibits both its original fossils and a reconstruction of this amazing specimen. Another one was found in 1905 in South Dakota, USA.

 

 

Other sauropods from the early Cretaceous, Andesaurus delgadoi and Rebbachisaurus Tessonei were found in El Chocón area. Also Unenlagia comahuensis a megaraptor from the late Cretaceous closely related with the birds, as it had wing-shaped forelimbs and, most likely, feathers. Also from this period is Patagonykus, another theropod with strong and short fore limbs armed only with a big nail.

 

Other site full of fossils in the Neuquén province is Rincón de los Sauces, north of the province, in the Colorado river valley.

 

In Río Negro province one of the best sites is Cinco Saltos, where there is a small museum exhibiting the only articulated specimen of Neuquensaurus australis, a Sauropod of the Titanosaurus group which lived in the late Cretaceous. In this area other Titanosaurus like Pellegrinisaurus and Rocasaurus were found, as well as Abelisaurus, another huge carnivore provided with a skull of almost one meter long, which is exhibited in the Cipoletti Museum.

 

 

The Chubut province is rich in fossils from the Jurassic (205 to 138 years ago), specially in the Cerro Cóndor area, where an entire family of Patagosaurus, another big sauropod, was found, as well as the carnivore Piatnitzkysaurus.

 

The finding of an extraordinary site near the town of El Sombrero with fossils of seven huge sauropods was recently on the covers of the international media. Among those, the researchers found a femur of 2,40 m., so they estimate the size of the dinosaur to be around 40 m., with a weight of around 80 Tons. If these data are confirmed this dinosaur, which is still unnamed until the research results are published, could replace Argentinosaurus as the biggest dinosaur ever found. Anyway, apart from these facts, that are always very attractive for the general public, the most important thing about this finding is its exceptional preservation state, and the fact that there is still a lot to discover. The research is leaded by a scientist group from the Egidio Feruglio Paleontology Museum, in the city of Trelew, Chubut.

 

 

In the south end of Patagonia, in Santa Cruz, amazing fossils have also been discovered. For example a nest with the offspring of Massaurus, a dinosaur of the Prosauropodha group that lived by the late Triassic (215 million years) on an environment of thick conifers forests whose petrified remains can be visited not at the Petrified Forests Natural Monument.

 

Also from Santa Cruz is the surprising finding of ichnites, or fossilized footprints, of species like Sarmientichnus, a two-toed theropod from the Upper Jurassic. These give us plenty of information about their behavior (e.g. if they moved alone or in groups) and how they walked. The footprints found show how Sarmientichnus walked using just two toes, as opposed to the three toes used by other theropods.