mandible

The mandible (from Latin mandibula, "jawbone") or inferior maxillary bone forms the lower jaw and holds the lower teeth in place. It also refers to both the upper and lower sections of the beaks of birds; in this case the "lower mandible" corresponds to the mandible of humans while the "upper mandible" is functionally equivalent to the human maxilla but mainly consists of the premaxillary bones. Conversely, in bony fish for example, the mandible may be termed "lower maxilla".
pictures of swans