supports a Middle Jurassic origin for titanosaurs, which implies the same for all neosauropods. Brachiosaurids in particular have a broad distribution dating to the Late Jurassic. Late Jurassic specimens have been discovered in the northern and southern Hemispheres, including North America, Africa, Europe, and South America. This suggests that brachiosaurids originated in the Middle Jurassic, prior to the breakup of Pangaea, followed by diversification and dispersal that resulted in the global spread present in the Late Jurassic. This conclusion is further supported by paleogeographic data. While many Late Jurassic dinosaur remains have been found in China, no brachiosaurid remains have been uncovered in East Asia. This would support the Middle Jurassic origin theory since East Asia was separated from the rest of Pangaea by water from the late Middle Jurassic to the Early Cretaceous. While brachiosaurids were widely dispersed in the Late Jurassic, their geographic distribution narrowed in the Early Cretaceous. So far, brachiosaurid specimens have only been found in the Aptian-Albian region of North America. This reduction in distribution occurs immediately following the Jurassic-Cretaceous boundary. The brachiosaurid distribution in the Early Cretaceous has been interpreted as a result of regional extinctions in Europe, Africa, and South America. Overall, the Early Cretaceous seems to be a time of reduced sauropod diversity worldwide. It has been argued that this change may be due to an extinction event at the Jurassic-Cretaceous boundary. A second hypothesis is that the apparent lack of geographical diversity is due to sampling bias in the generally poor Early Cretaceous fossil record. Recently discovered evidence supports the conclusion that brachiosaurids existed outside of North America in lower latitudes of Gondwana in the Early Cretaceous. In 2013, Mannion et al. reported on the discovery of two isolated teeth found in Lebanon from the Early Cretaceous that possess posteriorly twisted crowns, which are characteristic of the brachiosaurids Giraffatitan and Abydosaurus. In addition, a brachiosaurid named Padillasaurus leivaensis was discovered in Colombia from the Early Cretaceous and placed in the Brachiosauridae taxon, which suggests that Brachiosauridae survived in northwestern Gondwana after the Jurassic/Cretaceous boundary. In the Early Cretaceous, Colombia was located close to the equator in northwestern Gondwana while Lebanon was in the northeast of Gondwana. This suggests that brachiosaurids were in fact present outside of North America in the Early Cretaceous, and supports the theory that the apparent lack of specimens is due to an incomplete record. However, the rarity