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Flexibility: Ostrich and sauropod necks



Apologies if this was already posted, I may have missed it. Found this fascinating.

http://www.bbc.co.uk/news/science-environment-23679932

A study of modern-day ostriches suggests the ancient animals were probably quite stiff in their movement.

Sauropod dinosaurs had a thick mass of muscle in their necks and the researchers say this would probably have restricted the range over which the beasts could move their heads.
...


http://www.plosone.org/article/info%3Adoi%2F10.1371%2Fjournal.pone.0072187

Inter-Vertebral Flexibility of the Ostrich Neck: Implications for Estimating Sauropod Neck Flexibility

Matthew J. Cobley, Emily J. Rayfield, Paul M. Barrett

Abstract

The flexibility and posture of the neck in sauropod dinosaurs has long been contentious. Improved constraints on sauropod neck function will have major implications for what we know of their foraging strategies, ecology and overall biology. Several hypotheses have been proposed, based primarily on osteological data, suggesting different degrees of neck flexibility. This study attempts to assess the effects of reconstructed soft tissues on sauropod neck flexibility through systematic removal of muscle groups and measures of flexibility of the neck in a living analogue, the ostrich (Struthio camelus). The possible effect of cartilage on flexibility is also examined, as this was previously overlooked in osteological estimates of sauropod neck function. These comparisons show that soft tissues are likely to have limited the flexibility of the neck beyond the limits suggested by osteology alone. In addition, the inferred presence of cartilage, and varying the inter-vertebral spacing within the synovial capsule, also affect neck flexibility. One hypothesis proposed that flexibility is constrained by requiring a minimum overlap between successive zygapophyses equivalent to 50% of zygapophyseal articular surface length (ONP50). This assumption is tested by comparing the maximum flexibility of the articulated cervical column in ONP50 and the flexibility of the complete neck with all tissues intact. It is found that this model does not adequately convey the pattern of flexibility in the ostrich neck, suggesting that the ONP50 model may not be useful in determining neck function if considered in isolation from myological and other soft tissue data.

PLoS ONE 8(8): e72187. doi:10.1371/journal.pone.0072187