The recently described titanosaurid, Futalognkosaurus dukei, has the most complete skeleton known (all cervical and dorsal vertebrae and hip bones) for a sauropod of its enormous size (estimated at around 34 m), and was recovered from Argentinian Coniacian Cretaceous deposits that also yielded a wealth of other contemporaneous plant and animal fossils (Calvo et al., 2007).
Calvo, J.O., Porfiri, J.D., GonzŠlez-Riga, B.J., & Kellner, A.W.A. (2007). A new Cretaceous terrestrial ecosystem from Gondwana with the description of a new sauropod dinosaur. Anais da Academia Brasileira de CiÍncias 79 (3): 529-541.