Mechanism of intra-oral transport in a herbivore, the hyrax (Procavia syriacus).

Movements in the jaw, tongue and hyoid during feeding behaviour were recorded with cine-X-ray. Food was moved through the mouth by anterior/posterior motion of the tongue surface relative to the hard palate. This was true for both stage I transport, from the front of the mouth to the molar tooth row and stage II transport, from the molar tooth row to the vallecular area of the oropharynx. During a series of chew cycles, processed food collected in the oropharynx prior to a swallow. Swallows occurred as discrete events punctuating chew sequences and were characterized by coordinated movements of tongue and soft palate. Similar mechanisms of transport have been observed in the opossum and the cat, indicating a common mammalian behaviour. Differences between this herbivore and anthropoid primates can be attributed to differences in anatomy of the oral apparatus.