Patagosaurus

Phylogeny: Dinosauria > Saurischia > Sauropodomorpha > Plateosauria > Massopoda > Sauropodiformes > Sauropoda > Gravisauria > Eusauropoda > Cetiosauridae

Overview: True sauropods evolved towards the end of the Late Triassic, but it was during the latter part of the Early Jurassic that they began to truly flourish and diversify. One major clade to evolve in this time was the Eusauropoda, from which most of the popularly known sauropods evolved from; dinosaurs like Diplodocus, Brachiosaurus and the titanosaurs. Patagosaurus was a basal or “primitive” member of the eusauropod lineage. Specifically, it’s usually classified within the family Cetiosauridae. Cetiosaurids were more basal than some other eusauropod families, such as the mamenchisaurids. As a member, Patagosaurus was of course a close relative of Cetiosaurus itself, though it’s debated as to which other basal eusauropods truly belonged to the family. Both had a lot in common, though Patagosaurus lived in Argentina, while Cetiosaurus roamed England.

Cetiosaurids were mostly medium-sized sauropods. Patagosaurus grew to be about fifteen meters long and a handful of tons in weight. While this is considerably smaller than some other sauropods that evolved later, it was still one of the largest land animals of its time. Patagosaurus probably fed upon medium to high-level vegetation, with conifers making up a fair bit of its diet. It itself may’ve been a food source for theropods like Asfaltovenator and Piatnitzkysaurus. All three genera are based on fossils unearthed from Argentina’s Cañadón Asfalto Formation. While an obscure genus to the public at large, Patagosaurus is decently well known as far as fossils go. Up to a dozen or more partial specimens have been found, representing different growth stages. Patagosaurus was described in 1979 by the renowned José F. Bonaparte, its name referring to the region of Patagonia.