The Neck Posture of Brachiosaurus brancai

Abstract

Compressive forces acting on the intervertebral discs along the neck of Brachiosaurus brancai from the Late Jurassic of Tendaguru are calculated for different neck postures. The distribution of compressive forces along the neck is compared to the distribution of the cross-sectional areas of the intervertebral discs. Neck postures in which the pattern of compressive forces does not match the pattern of cross-sectional areas of the intervertebral discs are rejected. The neck posture of Brachiosaurus brancai must have been nearly vertical. A more inclined neck posture can only occasionally have been kept. Therefore, Brachiosaurus brancai appears to have been an extremely specialized high browser. In the same area, different sized individuals fed in different heights instead of each individual exploiting an extended vertical feeding range.