Conodonts
Conodonts
复制标题
DOI：
10.1007/978-81-322-3962-8_5
复制
发表时间：
2019-12
期刊：
影响因子：
--
通讯作者：
Sreepat Jain
中科院分区：
文献类型：
--
作者：
Sreepat Jain
牙形刺（=希腊语中的锥齿）通常是显微镜下（长度为0.2-2 mm）的生物体，尽管已经记录了罕见的高达25 mm的更大标本（Gabbian et al. 1995; Purnell 1995）。牙形刺是细长的、无盔甲的、鳗鱼状的、大眼睛的海洋动物（Briggs et al. 1983; Purnell 1995）（图1）。除了位于口腔和/或咽部的齿状磷酸盐（具有类似于橄榄石的结构的生物磷灰石）成分外，它们是软体动物（图2（1））。 图1早石炭纪（密西西比期迪纳第阶）Clydagnathuscf.cavusiformisRhodes et al.（1969）在苏格兰爱丁堡的格兰顿虾床中的线条图。根据Briggs et al.（1983）图2牙形石动物的修改。图1：显示牙形石动物主要形态特征的线条图。第二章：伊利诺斯州宾夕法尼亚期岩石中典型Scottognathus typicus（罗兹）牙形刺成分的自然组合（Scottognathus是Idiognathodus的次异名）（根据Sweet和Donoghue 2001）。第三章：牙形石动物头部的后腹视图，显示了Lochkovian（最早的泥盆纪）Pandorinellina rernscheidensis（齐格勒）（在Dzik 1991后修改）的元件（装置）的位置。图4：在动物暴露的口腔内，牙形石的M、S和P元素之间的关系。图5：两组P元素（P1和P2）的放大视图（根据Purnell和Jones 2012修改）
Conodonts (=cone -tooth in Greek) are usually microscopic (0.2–2 mm in length) organisms, although, rare larger specimens up to 25 mm have been recorded (Gabbott et al. 1995; Purnell 1995). Conodonts are elongate , armorless, eel-shaped, and large-eyed marine animals (Briggs et al. 1983; Purnell 1995) (Fig. 1). They are soft-bodied, except for their apparatus of tooth-like phosphatic (bioapatite with a francolite-like structure) elements situated in the mouth and/or the pharynx (Fig. 2(1)). Fig. 1Line drawing of the Early Carboniferous (Dinantian, Mississippian)Clydagnathuscf.cavusiformisRhodes et al. (1969) from the Granton Shrimp Bed (Edinburgh, Scotland).Modified from Briggs et al. (1983)Fig. 2The conodont animal. 1: Line drawing of the conodont animal showing its major morphological features. 2: A natural assemblage of conodont elements ofScottognathus typicus(Rhodes) from Pennsylvanian rocks in Illinois (Scottognathusis a junior synonym ofIdiognathodus) (after Sweet and Donoghue 2001). 3: The postero-ventral view of the head of the conodont animal showing the position of elements (apparatus) of the Lochkovian (earliest Devonian)Pandorinellina rernscheidensis(Ziegler) (modified after Dzik 1991). 4: Illustration of conodont’s M, S and P elements in relationship to one another within the animal’s exposed oral cavity . 5: Enlarged view of the two sets of P elements (P1and P2) (modified from Purnell and Jones 2012)