ZOO 4307C Chapter Notes -Sarcopterygii, Reedfish, Bichir
25 Feb 2014
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Document Summary
These ganoid scales are found in all of the primitive members of the group, ie covering the body of birchirs and the reedfish, forming the rows of scutes on the body of sturgeons. The scales of all living telosts are derived from this and consist of only a single layer of bone, called leptoid. Divided into acipenseriformes (sturgeons and paddlefish) and the polypteriformes (reedfishes and bichirs) Ganoin is a shiny substance that resembes enamle and is secreted by the corium of certain fishes. Dorsal fin is composed on 5-18 small finlets, each containing one stiff ray and one or more soft secondary rays, plus a membrane behind. Also have pectoral fins that are found on lobes. However, differ so much from those of sarcopterygian, people belived they evolved separately. Have scutes rather than scales (5 rows along body) Scutes are bony exteral plates or scales overlaid with horn, like a turtle shell.
