A new analysis of
ostriches1(鸵鸟) reveals that a computer model of long-necked
sauropods(蜥脚类动物) used to simulate the
dinosaurs3' movements, featured in BBC's Walking with Dinosaurs and the focus of an installation at the American Museum of Natural History, New York, does not correctly reconstruct how flexible their necks were. The results are published August 14 in the open access journal PLOS ONE by Matthew Cobley from the University of Utah, with colleagues from the University of Bristol and Natural History Museum, London.
Previous estimates of sauropod neck
flexibility4 were based on the positions of neck vertebrae, but this new research suggests these estimates were probably
inaccurate5, as the models don't account for the effects of soft tissues like muscle and
cartilage(软骨). This analysis of ostriches, close relatives of the long-necked sauropod dinosaurs, reveals that increasing muscle mass in the neck reduces the maximum flexibility of their necks. Variations in the distance between vertebral
joints6 and the amount of cartilage present in the neck could also have reduced the flexibility of sauropods' long necks, according to this research.
Museum exhibits and movies often
depict7 sauropods arching their necks into a wide range of movements, all the way from tree-tops to low vegetation. However, the results of this study indicate that these dinosaurs may have been less flexible than typically
depicted8. Having less flexible necks would have likely restricted the range of foods these dinosaurs could reach, their
ecological9 niches10, and consequently, they may have
foraged11 more
actively12 to meet their average dietary needs of approximately 400 kg of plant matter each day.
Cobley adds, "I believe the most important thing to take away from this study is that computer modeling of any biological system -- be it anything from an individual organ to a whole
dinosaur2 -- needs to be 'ground-truthed' before it is accepted by the scientific community and presented to the public. It's easy to be swayed by these beautifully reconstructed models of dinosaurs, but if these models aren't based on real, empirical data taken from living animals we can actually study, they only serve to confuse the general public."