A re-evaluation of the Ordovician cystoidStichocystisJaekel and the taxonomic implications
作者:
JohanFredrik Bockelie,
期刊:
Geologiska Föreningen i Stockholm Förhandlingar
(Taylor Available online 1981)
卷期:
Volume 103,
issue 1
页码: 51-59
ISSN:0016-786X
年代: 1981
DOI:10.1080/11035898109455204
出版商: Taylor & Francis Group
关键词: Stichocystis;Caryocystitidae;Caryocystitida;Rhombifera;Cystoidea;taxonomy;Ordovician;Amtjärn;Kullsberg;central Dalarna;central Sweden;N6055 N6057 E1506 E1504
数据来源: Taylor
摘要:
Stichocystisis re-described. The genus is a rhombiferan with exothecal pore structures developed in a rhomb-in-rhomb pattern with canals embedded within narrow calcite ridges. The pore system developed by regular addition of new sutural pores which later in ontogeny became separated by a calcite ridge as the canal grew outwards from the suture. This type of pore structure is highly specialized. The plate configuration of the oral-anal area clearly putsStichocystisamongst the Caryocystitidae and close to the generaHeliocrinitesandLophotocystiswith which it shares many characteristics. The two orders of the Rhombifera, the Dichoporita and the Fistuliporita reflect two fundamentally different types of pore structures, endothecal and exothecal. With regard to these structures, the order Fistuliporita is more closely related to the Class Diploporita than to the Dichoporita.
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