Answer: premaxilla bone (or maxilla) and the maxillary beak (or rhinotheca).
Explanation:
The beak is composed of keratin, the same tough, insoluble protein found in fingernails, hoofs, antlers and horns. A bird's bill comprises two parts. The upper portion of a bird's bill is called the maxillary rostrum, which consists of the premaxilla bone (or maxilla) and the maxillary beak (or rhinotheca).
