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Conodonts (Greek ''kōnos'', "cone", + ''odont'', "tooth") are extinct chordates resembling eels, classified in the class Conodonta. For many years, they were known only from tooth-like microfossils found in isolation and now called conodont elements. Knowledge about soft tissues remains limited. The animals are also called Conodontophora (conodont bearers) to avoid ambiguity. Conodont teeth are the earliest found in the fossil record. == Description == The 11 known fossil imprints of conodont animals record an eel-like creature with 15, or more rarely, 19 elements that form a bilaterally symmetrical array in the head. This array constituted a feeding apparatus that is radically different from the jaws of modern animals. The three forms of teeth, i.e., coniform cones, ramiform bars, and pectiniform platforms, may have performed different functions. The organisms range from a centimeter or so to the large ''Promissum'', 40 cm in length. It is now widely agreed that conodonts had large eyes, fins with fin rays, chevron-shaped muscles and a notochord. The entire class of conodonts is postulated to have been wiped out in the Triassic–Jurassic extinction event, which occurred roughly 200 million years ago.〔(The extinction of conodonts —in terms of discrete elements— at the Triassic-Jurassic boundary )〕 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「conodont」の詳細全文を読む スポンサード リンク
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