oppose vertically, comprising an upper jaw and a lower jaw and can bear numerous ordered teeth. Cartilaginous fishes grow multiple sets (polyphyodont) and...

The Osteostraci (bony armored jawless fish) are generally considered the sister taxon of Gnathostomata. Jaw development in vertebrates is likely a product...

armoured fish known as ostracoderms, first appeared. Most jawless fish are now extinct; but the extant lampreys may approximate ancient pre-jawed fish. Lampreys...

numerous teeth. The vertebrate jaw probably originally evolved in the Silurian period and appeared in the Placoderm fish which further diversified in the...

response to their diet. Fish that ate hard-shelled prey had a robust jaw with molar-like teeth fit for crushing their durable prey. Fish that ate softer prey...

and has longer pectoral fins. The sling-jaw wrasse possesses the most extreme jaw protrusion found among fishes. The species can extend its jaws up to...

(khóndros) 'cartilage' and ἰχθύς (ikhthús) 'fish') is a class of jawed fish that contains the cartilaginous fish or chondrichthyans, which all have skeletons...

digits. Fish can be grouped into the more basal jawless fish and the more common jawed fish, the latter including all living cartilaginous and bony fish, as...

A fish scale is a small rigid plate that grows out of the skin of a fish. The skin of most jawed fishes is covered with these protective scales, which...

Prehistoric fish are early fish that are known only from fossil records. They are the earliest known vertebrates, and include the first and extinct fish that...