Patagosaurus

Patagosaurus (meaning "Patagonia lizard") is an extinct genus of eusauropod dinosaur from the middle Toarcian of Patagonia, Argentina. It was first found in deposits of the Cañadón Asfalto Formation, which date to around 178 million years ago. Although originally twelve specimens were assigned to the taxon, at least one of them may belong to a different genus. Patagosaurus probably lived alongside genera such as Piatnitzkysaurus, Condorraptor, and Volkheimeria.

Since Patagosaurus is known from many specimens, including at least one juvenile, its anatomy and growth are fairly well understood. Both ages exhibit the typical features of a sauropod: a long neck, small head, a long tail, and quadrupedal stance. The juvenile exhibits features different from the adult in regions like the mandible, pectoral girdle, pelvis, and hindlimb, although overall their anatomy is quite similar. The many known specimens help fill in gaps in the anatomy of the genus, such as the forelimb and skull. Parts of the skeleton, like the pectoral girdle, tibia, and pubis are more robust, while others, like the forelimb and ischium, are more gracile. The material of Patagosaurus is similar to closely related taxa like Cetiosaurus and Volkheimeria, more primitive genera such as Barapasaurus and Amygdalodon, and more derived sauropods like Diplodocus and Camarasaurus.