Lusotitan is a herbivorous sauropod dinosaur belonging to the brachiosaurid group, originating from the Late Jurassic Period in Portugal. This remarkable sauropod attained substantial size, measuring 21 meters (69 feet) in length and weighing around 30 tonnes (33 short tons). Notably, it possessed elongated forelimbs, with the humerus and femur reaching lengths of 2.05 meters (6.7 feet) and 2 meters (6.6 feet), respectively.

The initial discovery of Lusotitan dates back to 1947 when the first fossils were unearthed. These findings were subsequently classified as a species of Brachiosaurus by Albert-Félix de Lapparent and Georges Zbyszewski in 1957. However, in 2003, Octávio Mateus and Miguel Telles Antunes reclassified these fossils as Lusotitan atalaiensis. Their decision was based on the observation that the differences between the specimens exceeded what would typically be expected at the species level.

Although the complete skull of Lusotitan remains unknown, it is reasonable to assume it would resemble the skulls of other members within the brachiosaurid group. Remarkably, Lusotitan is not the only dinosaur originally believed to be exclusive to North America that has been subsequently discovered in Portugal. Fossils of Stegosaurus have also been located in Portugal, strengthening the hypothesis that a land bridge connection existed between Western Europe and North America towards the end of the Jurassic period.