Diplodocoidea

Diplodocoidea is a clade of sauropod dinosaurs within the larger group Sauropoda and the clade Neosauropoda. It includes several families, notably Dicraeosauridae, Diplodocidae, and Rebbachisauridae. The group existed from the Early Jurassic to the Late Cretaceous, with fossils found in North America, Africa, South America, Europe, and Asia, indicating a widespread distribution across major landmasses.

Anatomically, diplodocoids are characterized by long necks and tails and relatively small heads. Diplodocidae, the best-known family, includes genera such as Diplodocus and Barosaurus and is distinguished by extremely long, slender skulls and elongated necks and tails. Dicraeosauridae members tend to have shorter necks and more robust bodies, while Rebbachisauridae shows more variation in skull and postcranial anatomy.

Ecology: Diplodocoids were terrestrial herbivores. Their body plans suggest a range of feeding strategies from low- to mid-height browsing to more generalized grazing, depending on lineage. The long necks could allow feeding over a wide area with limited movement of the body, and substantial limb strength supported their large size. Fossils are known from diverse habitats, including floodplains and woodlands.

Evolution and classification: In most phylogenetic analyses, Diplodocoidea represents one of the two major neosauropod clades, alongside Macronaria, within Sauropoda. Within Diplodocoidea, the principal families are Dicraeosauridae, Diplodocidae, and Rebbachisauridae; exact relationships among them vary by study. Diplodocoids are among the better-represented sauropods in the fossil record and have contributed important insights into sauropod evolution and paleobiogeography.