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是一种化石的名字，棱菊石，已经灭绝了棱菊石目（Goniatitida）是一群已经灭绝的菊石亚纲生物，与乌贼、章鱼关系较接近，与鹦鹉螺关系较远。棱菊石目最早出现在泥盆纪早期(大约4亿 年前)，兴盛于石炭纪与二迭纪，最后于古生代末期，约2亿4500万年前灭绝。 所有的棱菊石类都拥有外壳，硬壳内部被隔板分隔成独立的壳室，壳室里可能都充满着气体。大部分的棱菊石类直径都小于15公分，甚至常常小于5公分。棱菊石 类的外壳通常都具有螺旋状的花纹，与中生代的菊石类不同。中生代的菊石类外壳大部分只有部分螺旋花纹，有些种类甚至没有螺旋花纹维基百科的英文原文GoniatiteFrom Wikipedia, the free encyclopediaGoniatites are an extinct group of ammonoid, which are shelled cephalopods related to squids, belemnites, octopuses, and cuttlefish, and more distantly to the nautiloids. Early in the Devonian period, some 400 million years ago, goniatites originated from within the more primitive anarcestine ammonoids. Surviving the Late Devonian biotic crises, goniatites flourished during the Carboniferous and Permian periods and finally became extinct in the Permian–Triassic extinction event at the close of the Paleozoic Era some 251.4 million years ago. They were survived by their cousins the ceratite ammonoids, also descendants of the anarcestine ammonoids.The goniatites all possessed an external shell, which is divided internally into chambers. The animal lived in the largest of the external chambers, and the internal chambers would have been filled with gas, making the animal buoyant in the water. The general structure of the goniatites would have been similar to that of their relatives the ammonites, being a free swimming animal possessing a head with two well developed eyes and arms (or tentacles).A polished Goniatite fossilGoniatites are small to medium in size, almost always being less than 15 centimetres (6 inches) in diameter and often smaller than 5 centimetres (2 inches) in diameter. The shell is always planispirally coiled, unlike that of the later ammonites of the Mesozoic era, some of which evolved into partially coiled or completely uncoiled forms (called heteromorphs). The shape of most goniatite shells suggests that they were poor swimmers.The thin walls between the internal chambers of the shell are called the septa, and as the goniatite grew it would move its body forward in the shell secreting septa behind it, thereby adding new chambers to the shell. The sutures (or suture lines) are visible as a series of narrow, wavy lines on the surface of the shell. The sutures appear where each septa contacts the wall of the outer shell.A distinctive feature of the goniatites is the
