The Soft Palate Enables Extreme Feeding and Explosive Breathing in the Fin Whale ().

The evolution of lunge feeding in rorqual whales was associated with the evolution of several unique morphological features that include non-synovial ligamentous temporomandibular joints, a tongue that can invert and extend backward to the umbilicus, walls of the oral cavity that can dramatically expand, and muscles and nerves that are stretchy. Also, among the acquired features was an enlargement of the rostral end of the soft palate into an oral plug that occludes the opening between the oral cavity and pharynx and prevents water incursion into the pharynx during the engulfment phase of a feeding lunge. During this engulfment phase of a lunge, the volume of water entering the oral cavity can exceed the volume of the whale itself.

Morphology and Mechanics of the Fin Whale Esophagus: The Key to Fast Processing of Large Food Volumes by Rorquals.

Lunge feeding rorqual whales feed by engulfing a volume of prey laden water that can be as large as their own body. Multiple feeding lunges occur during a single foraging dive and the time between each lunge can be as short as 30 s (Goldbogen et al. 2013).

Retia mirabilia: Protecting the cetacean brain from locomotion-generated blood pressure pulses.

Cetaceans have massive vascular plexuses (retia mirabilia) whose function is unknown. All cerebral blood flow passes through these retia, and we hypothesize that they protect cetacean brains from locomotion-generated pulsatile blood pressures. We propose that cetaceans have evolved a pulse-transfer mechanism that minimizes pulsatility in cerebral arterial-to-venous pressure differentials without dampening the pressure pulses themselves.

Woodpeckers minimize cranial absorption of shocks.

The skull of a woodpecker is hypothesized to serve as a shock absorber that minimizes the harmful deceleration of its brain upon impact into trees and has inspired the engineering of shock-absorbing materials and tools, such as helmets. However, this hypothesis remains paradoxical since any absorption or dissipation of the head's kinetic energy by the skull would likely impair the bird's hammering performance and is therefore unlikely to have evolved by natural selection. In vivo quantification of impact decelerations during pecking in three woodpecker species and biomechanical models now show that their cranial skeleton is used as a stiff hammer to enhance pecking performance, and not as a shock-absorbing system to protect the brain.

Anatomical mechanism for protecting the airway in the largest animals on earth.

Separation of respiratory and digestive tracts in the mammalian pharynx is critical for survival. Food must be kept out of the respiratory tract, and air must be directed into the respiratory tract when breathing. Cetaceans have the additional problem of feeding while underwater.