Dicraeosaurids

Dicraeosaurids are a family of sauropod dinosaurs within the larger group Diplodocoidea. They lived from the Middle Jurassic to the Early Cretaceous and fossils have been found in Africa and South America. The group is recognized for a tendency toward smaller body size among sauropods and, in some members, a relative reduction in neck length compared with other diplodocoids.

Notable genera include Dicraeosaurus from the Tendaguru Formation of Tanzania (Late Jurassic) and Amargasaurus from Patagonia (Argentina, Early Cretaceous). Brachytrachelopan, also from South America, is another dicraeosaurid known for its unusually short neck. These taxa illustrate the diversity of the group, which ranges from compact, robust forms to species with distinctive vertebral features.

Anatomically, dicraeosaurids typically possessed small skulls and peg-like teeth adapted to a herbivorous diet. Their vertebral columns often show relatively modest neural spines compared with some other sauropods, though the spines can be notably tall in certain lineages such as Amargasaurus. Limb proportions indicate quadrupedal locomotion, and their postcranial anatomy suggests life habits that differ in some ways from the longer-necked diplodocids.

Ecologically, dicraeosaurids inhabited forested and floodplain environments where they would have browsed on vegetation at mid to low heights. They coexisted with other sauropods and contemporaneous herbivores, contributing to the diversity of sauropod faunas during the Jurassic–early Cretaceous transition. The group’s distinctive mix of neck length, body size, and spine morphology provides important clues about sauropod evolution and ecological diversification.