Search results
Results From The WOW.Com Content Network
The upper jaw, or maxilla [12] [13] is a fusion of two bones along the palatal fissure that form the upper jaw. This is similar to the mandible (lower jaw), which is also a fusion of two halves at the mandibular symphysis. In bony fish, the maxilla is called the "upper maxilla," with the mandible being the "lower maxilla".
In non-mammalian synapsids, the jaw is composed of four bony elements and referred to as a quadro-articular jaw because the joint is between the articular and quadrate bones. In therapsids (advanced synapsids including mammal), the jaw is simplified into an articulation between the dentary and the squamous part of the temporal bone , and hence ...
Caudal/Tail fins: Also called the tail fins, caudal fins are attached to the end of the caudal peduncle and used for propulsion. The caudal peduncle is the narrow part of the fish's body. The hypural joint is the joint between the caudal fin and the last of the vertebrae. The hypural is often fan-shaped.
In all jawed fish (gnathostomes), the first arch pair (mandibular arches) develops into the jaw, the second gill arches (the hyoid arches) develop into the hyomandibular complex (which supports the back of the jaw and the front of the gill series), and the remaining posterior arches (simply called branchial arches) support the gills.
The lower jaw and maxilla are then pulled back to close the mouth, and the fish is able to grasp the prey. By contrast, mere closure of the jaws would risk pushing food out of the mouth. By contrast, mere closure of the jaws would risk pushing food out of the mouth.
Skeletal head of an Amia calva.Hyamandibular marked h, top image, upper right corner. The hyomandibula, commonly referred to as hyomandibular [bone] (Latin: os hyomandibulare, from Greek: hyoeides, "upsilon-shaped" (υ), and Latin: mandibula, "jawbone"), is a set of bones that is found in the hyoid region in most fishes.
Discover the latest breaking news in the U.S. and around the world — politics, weather, entertainment, lifestyle, finance, sports and much more.
In early fish and in chondrichthyans (cartilaginous fish such as sharks), Meckel's cartilage continued to be the main component of the lower jaw. But in the adult forms of osteichthyans (bony fish) and their descendants ( amphibians , reptiles , birds , and mammals ), the cartilage is covered in bone – although in their embryos the jaw ...