Il parait que les mini vaches couraient lol

Posté par Markvantomme il y a 17 ans

J'ai piqué ça a la DML

Chez les archosaures on a trouvé ce processs que chez Talenkauen et Thescelosaurus qui sont mini vaches et aussi chez les crocodiles.. quoique cartilagineux.. bizarre lol
Ces machins aidaient la respiration et sont liés au style de locomotion.
J'imagine une mini vache sale bete en train de courir partout avant de devenir hamburguer de theropode lol

Peter G. Tickle, A. Roland Ennos, Laura E. Lennox, Steven F. Perry, and Jonathan R. Codd (2007). Functional significance of the uncinate
processes in birds. Journal of Experimental Biology 210: 3955-3961.

Summary: The functional significance of the uncinate processes to the ventilatory mechanics of birds was examined by combining analytical modeling with morphological techniques. A geometric model was derived to determine the function of the uncinate processes and relate their action to morphological differences associated with locomotor specializations. The model demonstrates that uncinates act as levers, which improve
the mechanical advantage for the forward rotation of the dorsal ribs and therefore lowering of the sternum during respiration. The length of these processes is functionally important; longer uncinate processes increasing the mechanical advantage of the Mm. appendicocostales muscle during inspiration. Morphological studies of four bird species showed that the uncinate process increased the mechanical advantage by factors of 2–4. Using canonical variate analysis and analysis of variance we then
examined the variation in skeletal parameters in birds with different primary modes of locomotion (non-specialists, walking and diving). Birds clustered together in distinct groups, indicating that uncinate length is more similar in birds that have the same functional constraint, i.e. specialization to a locomotor mode. Uncinate processes are short in walking birds, long in diving species and of intermediate length in non-specialist birds. These results demonstrate that differences in the breathing mechanics of birds may be linked to the morphological adaptations of the ribs and rib cage associated with different modes of locomotion.