FRONTOMANDIBULAR STAY OF BALAENOPTERIDAE - A MECHANISM FOR MOMENTUM RECAPTURE DURING FEEDING

The feeding process of Balaenopteridae (rorquals) is characterized by an energetic event in which a large volume of seawater is engulfed and filtered. Here we identify a major structural component of a stay app aratus that exists in the rorqual craniomandibular system. This fibrou s appendage of the temporalis muscle introduces a continuous, mechanic al linkage between the supraorbital process of the frontal bone and th e coronoid process of the mandible. It is named the frontomandibular s tay. Anatomic relationships and biomechanical findings predict that th is structure would control and assist a process of continuous change i n position of the jaws during engulfment events. The dynamic form of m andibular kinesis produced would function to increase the power of fee ding. Owing to the stay's nonmuscular construction, its mechanical act ion necessarily is driven by the kinetic mass of the moving whale.