论文部分内容阅读
基于一个呈正、反面保存,完整愈合的齿圈标本,描述了产自湖北荆门子陵下二叠统栖霞组灰岩中发现的旋齿鲨属一新种—荆门旋齿鲨(Helicoprion jinmenense sp.nov.).标本具有413圈的椭螺旋形齿圈;齿冠切叶较宽,且从3个半齿圈的开始,宽度大于高度;中部的高度大于切叶的高度;基部较短;外部2个齿圈相邻二齿冠间存在明显的“不被珐瑯质覆盖的间隙”;复合齿根高度中等,中央凹槽高度约为同一齿冠高度的1/10;脉管孔位于齿冠中部靠下;海绵状齿骨质层发育.与国外已知的旋齿鲨分子相比,与H.ferrieri和H.bessonowi存在一定的相似性,但H.ferrieri的切叶较短,基部较长、复合齿根较宽.而H.bessonowi除了具有一个相对较宽的复合齿根外,每一个齿圈上齿冠的数目大于40个,多于新种每一个齿圈上齿冠的数目.新种在总体形态、大小和组织学特点上与中国以往所报道的旋齿鲨类化石不同,但由于后者模式标本保存的不完备性,因此,很难确定它们之间的相互关系.新种不仅是中国境内迄今所发现的最完整的旋齿鲨类齿旋化石,而且也是中国首次发现的旋齿鲨属化石,具有重要的生物学、生物地层划分对比和生物地理意义.
Based on a ring-shaped specimen preserved positive and negative and completely healed, Helicoprion jinmenense sp., A new species of the genus Geranium, found in the Permian Qixia Formation limestone in Jingmen Ziwu, Hubei Province, is described. nov.) Specimens have an elliptical helical toothing of 413 turns; the crown has a relatively wide leaf cut and is wider than the height from the beginning of the three halves; the height of the middle is greater than the height of the cut leaf; the base is shorter; Two ring gear adjacent two teeth between the crown there is a clear “not covered by the enamel ”; composite root height is medium, the central groove height is about the same crown height of 1/10; The middle of the crown was lower and the spongy layer of spongeous tooth was developed.Compared with foreign known shark sharks, H.ferrieri and H.bessonowi had some similarities, but H.ferrieri had shorter cut leaves, The base is longer, the composite root is wider, while H. bessonowi has more than 40 crowns per ring, in addition to having a relatively wide composite root, more than the crown of each new ring The new species is different in general morphology, size and histological characteristics from the previously reported spinous shark fossils in China Therefore, it is difficult to determine the relationship between them.The new species is not only the most complete spinosa shark type fossil found in China, but also the first one discovered in China The genus Coria is a fossil with important biology, biological stratigraphic contrast and biogeographical significance.