Reconstruction of the cervical skeleton posture of Brachiosaurus brancai Janensch, 1914 by an analysis of the intervertebral stress along the neck and a comparison with the results of different approaches

✍ Scribed by Andreas Christian; Gordon Dzemski

• Publisher: John Wiley and Sons
• Year: 2007
• Tongue: English
• Weight: 375 KB
• Volume: 10
• Category: Article
• ISSN: 1435-1943
• DOI: 10.1002/mmng.200600017

✦ Synopsis

The neck posture of Brachiosaurus brancai Janensch, 1914 is reanalysed by employing the Preuschoft method to deduce the pattern of stress in the joints between the vertebral centra along the neck. The cogency of different methods for reconstructing the posture of a long neck, especially the Preuschoft method and approaches that are based on optimal articulation of the neck vertebrae, is discussed critically. The results corroborate the reliability of the Preuschoft method whereas the analyses of recent vertebrates with long necks show that approaches based on optimal articulation of the neck vertebrae are less suited for reconstructing habitual postures of long necks during rest. Such models are better suited for reconstructing the neck posture that was employed during locomotion. With the evidence obtained by different methods a conclusive picture of the neck posture and the feeding strategy of Brachiosaurus brancai can be drawn. The neck appears to have been slightly S-shaped with a ventrally flexed cranial section, an approximately straight middle section, and a dorsally flexed proximal part. In the habitual posture during standing, the angle between the middle section of the neck and the horizontal plane was about 60 or 70 . During locomotion the whole neck probably was kept in an lower position with the inclination reduced by approximately 20 compared with the position at rest. During feeding movements of the head relative to the neck and movements in the cranial neck section were performed without much altering the height of the centre of gravity of the neck. With slow dorsoventral movements of the whole neck pronounced changes in the feeding height were possible. Sideways movements of the whole neck were performed by lateral flexion at the base of the neck. According to these findings, the long neck of Brachiosaurus brancai was a means for browsing in great heights as well as a means for increasing the feeding volume without moving the body.