Given the question: Information: - The superclass Tetrapoda (Ancient Greek s tetrapods, "four-footed"), or the tetrapods , comprises the first four-limbed vertebrates and their descendants, including the living and extinct amphibians, birds, mammals, reptiles and some ancient, exclusively aquatic creatures such as the Acanthostega. Tetrapods evolved from the lobe-finned fishes around 390 million years ago in the middle Devonian Period, with modern tetrapod groups having appeared by the late Devonian, 367.5 million years ago. The specific aquatic ancestors of the tetrapods, and the process by which land colonization occurred, remain unclear, and are areas of active research and debate among palaeontologists at present. - Vertebrates comprise all species of animals within the subphylum Vertebrata (chordates with backbones). Vertebrates represent the overwhelming majority of the phylum Chordata, with currently about 64,000 species described. Vertebrates include the jawless fish and the jawed vertebrates, which include the cartilaginous fish (sharks and rays) and the bony fish. - A symphysis is a fibrocartilaginous fusion between two bones. It is a type of cartilaginous joint, specifically a secondary cartilaginous joint. - The skull is a bony structure that forms the head of the skeleton in most vertebrates. It supports the structures of the face and provides a protective cavity for the brain. The skull is composed of two parts: the cranium and the mandible. In the human these two parts are the neurocranium and the viscerocranium or facial skeleton that includes the mandible as its largest bone. The skull forms the anterior most portion of the skeleton and is a product of cephalisationhousing the brain, and several sensory structures such as the eyes, ears, nose, and mouth. In the human these sensory structures are part of the facial skeleton. - In biological anatomy, commonly referred to as the mouth, under formal names such as the oral cavity, buccal cavity, or in Latin cavum oris, is the opening through which many animals take in food and issue vocal sounds. It is also the cavity lying at the upper end of the alimentary canal, bounded on the outside by the lips and inside by the pharynx and containing in higher vertebrates the tongue and teeth. This cavity is also known as the buccal cavity, from the Latin "bucca" ("cheek"). - The tongue is a muscular organ in the mouth of most vertebrates that manipulates food for mastication, and is used in the act of swallowing. It is of importance in the digestive system and is the primary organ of taste in the gustatory system. The tongue's upper surface (dorsum) is covered in taste buds housed in numerous lingual papillae. It is sensitive and kept moist by saliva, and is richly supplied with nerves and blood vessels. The tongue also serves as a natural means of cleaning the teeth. A major function of the tongue is the enabling of speech in humans and vocalization in other animals. - Cheeks constitute the area of the face below the eyes and between the nose and the left or right ear. "Buccal" means relating to the cheek. In humans, the region is innervated by the buccal nerve. The area between the inside of the cheek and the teeth and gums is called the vestibule or buccal pouch or buccal cavity and forms part of the mouth. In other animals the cheeks may also be referred to as jowls. - The nasal cavity (or nasal fossa) is a large air filled space above and behind the nose in the middle of the face. Each cavity is the continuation of one of the two nostrils. - The facial skeleton, viscerocranium, or splanchnocranium consists of a part of the skull that is derived from the pharyngeal arches. The facial bones are the bones of the anterior and lower skull. The rest of the skull is the neurocranium. - The maxillae ( plural : maxillae / mksli / ) are the two maxilla bones forming the upper jaw and palate of the mouth . The two halves are fused at the intermaxillary suture to form the upper jaw . This is similar to the mandible ( lower jaw ) , which is also a fusion of two halves at the mandibular symphysis . Sometimes ( e.g. in bony fish ) , the maxilla is called '' upper maxilla , '' with the mandible being the '' lower maxilla . '' Conversely , in birds the upper jaw is often called '' upper mandible . '' - The pharynx (plural: pharynges) is the part of the throat that is behind the mouth and nasal cavity and above the oesophagus and the larynx, or the tubes going down to the stomach and the lungs. The pharynx is an organ found in vertebrates and invertebrates, though the structure is not universally the same across all of those species. - In the facial skeleton of the skull the external surface of the mandible is marked in the median line by a faint ridge, indicating the mandibular symphysis, or symphysis menti, or line of junction where the two lateral halves of the mandible fused at an early period of life. It is not a true symphysis as there is no cartilage between the two sides of the mandible. - The hard palate is a thin horizontal bony plate of the skull, located in the roof of the mouth. It is formed by the palatine process of the maxilla and horizontal plate of palatine bone, and spans the arch formed by the upper teeth. - The soft palate (also known as the velum or muscular palate) is, in mammals, the soft tissue constituting the back of the roof of the mouth. The soft palate is distinguished from the hard palate at the front of the mouth in that it does not contain bone. - Mammals are any vertebrates within the class Mammalia (from Latin "mamma" "breast"), a clade of endothermic amniotes distinguished from reptiles and birds by the possession of a neocortex (a region of the brain), hair, three middle ear bones and mammary glands. The sister group of mammals may be the extinct "Haldanodon." The mammals represent the only living Synapsida, which together with the Sauropsida form the Amniota clade. The mammals consist of the Yinotheria including monotrema and the Theriiformes including the theria. - The palate is the roof of the mouth in humans and other mammals. It separates the oral cavity from the nasal cavity. A similar structure is found in crocodilians, but, in most other tetrapods, the oral and nasal cavities are not truly separate. The palate is divided into two parts, the anterior bony hard palate, and the posterior fleshy soft palate (or velum). What object entity has the relation of 'part of' with the subject 'maxilla'? Choices: - anatomy - animals - back - bones - breast - class - face - fish - hair - head - joint - life - mouth - nose - oesophagus - organ - palate - part - roof - skeleton - skull - species - the middle - throat
The answer is:
skull