TY - JOUR
T1 - Inter-vertebral flexibility of the ostrich neck
T2 - implications for estimating sauropod neck flexibility
AU - Cobley, Matthew J.
AU - Rayfield, Emily J
AU - Barrett, Paul, M.
PY - 2013/8/14
Y1 - 2013/8/14
N2 - 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 intervertebral
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
AB - 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 intervertebral
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
U2 - 10.1371/journal.pone.0072187
DO - 10.1371/journal.pone.0072187
M3 - Article (Academic Journal)
C2 - 23967284
SN - 1932-6203
VL - 8
JO - PLoS ONE
JF - PLoS ONE
IS - 8
M1 - e72187
ER -