FISHES AND TETRAPODS IN THE UPPER PENNSYLVANIAN (KASIMOVIAN) COHN COAL MEMBER OF THE MATTOON FORMATION OF ILLINOIS, UNITED STATES: SYSTEMATICS, PALEOECOLOGY, AND PALEOENVIRONMENTS
FISHES AND TETRAPODS IN THE UPPER PENNSYLVANIAN (KASIMOVIAN) COHN COAL MEMBER OF THE MATTOON FORMATION OF ILLINOIS, UNITED STATES: SYSTEMATICS, PALEOECOLOGY, AND PALEOENVIRONMENTS
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DOI：
10.2110/palo.2010.p10-121r
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发表时间：
2011-10
期刊：
影响因子：
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通讯作者：
D. Carpenter;H. Falcon-Lang;M. Benton;W. Nelson
中科院分区：
文献类型：
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作者：
D. Carpenter;H. Falcon-Lang;M. Benton;W. Nelson
摘要报道了在美国伊利诺斯州东南部马通组上宾夕法尼亚阶（中-上卡西莫阶）科恩煤段中发现的一个新的脊椎动物组合。牙齿，鳞片，和刺xenacanths（Dicentrodus，Orthacanthus，Triodus，Xenacanthus）和euselachian（Sphenacanthus）鲨鱼占主导地位的组合。不太常见的是全头类（Helodus）和辐鳍类鱼类的牙齿、鳞片和椎体，以及罕见的四足动物（主要是海龙类）趾骨和椎体。该组合发生在一个广泛的，浅的通道切割成一个突出的变性土。该通道被解释为在季节性干燥的冰川期海平面较低时被切断，但在随后的海侵期间被冰川消退触发填充。我们解释这是一个微咸水（河口）组合，根据脊椎动物的材料与spirorbids（假定的microconchids）和古生态推断收集的文献处理宾夕法尼亚州鱼类生态的批判性分析的共同出现。这种解释与埋藏学数据和鲨鱼物质的87 Sr/86 Sr同位素分析结果基本一致。然而，盘龙类化石可能是从低水位的变性土中重新形成的，这些动物占据了冰川期形成的旱地生态位。
ABSTRACT A newly discovered vertebrate assemblage is reported from the Upper Pennsylvanian (mid- to upper Kasimovian) Cohn Coal Member of the Mattoon Formation of southeast Illinois, United States. Teeth, scales, and spines of xenacanth (Dicentrodus, Orthacanthus, Triodus, Xenacanthus) and euselachian (Sphenacanthus) sharks dominate the assemblage. Less common are the teeth, scales, and centra of holocephalan (Helodus) and actinopterygian fishes, together with rare tetrapod (mainly pelycosaur) phalanges and centra. The assemblage occurs within a broad, shallow channel incised into a prominent Vertisol. The channel is interpreted as having been cut during a seasonally dry glacial phase when sea level was low, but filled during a subsequent transgression triggered by deglaciation. We interpret this as a brackish water (estuarine) assemblage, based on the co-occurrence of the vertebrate material with spirorbids (putative microconchids) and paleoecological inferences gleaned from a critical analysis of the literature dealing with Pennsylvanian fish ecology. This interpretation is broadly consistent with taphonomic data and the results of 87Sr/86Sr isotope analysis of shark material. The pelycosaur material may have been reworked from the lowstand Vertisol, however, and these animals occupied dryland niches that developed during glacial phases.