کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
5786406 | 1640636 | 2017 | 4 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Two rare taxa from the type area of the Devonian, south-west England
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کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
پیش نمایش صفحه اول مقاله
چکیده انگلیسی
The rarity of certain taxa in the type Devonian, south-west England, may be real, but it is probably, in part, an artefact of preservation. In part this is a product of Variscan deformation, but disarticulation of multi-element skeletons into minute plates must also be a contributory factor. Echinoids are rare from these deposits and were hitherto limited to the Upper Devonian. A single radiole (=spine) from the Middle Devonian (Givetian) Lummaton Shell Beds, Torquay Limestone Formation, is referred to echinoid sp. indet. Although stromatoporoids are common in these same beds, true sponges were hitherto unknown. In the same rock specimen, a moderately well preserved siliceous spicule is referred to octactinellid sp. indet.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Proceedings of the Geologists' Association - Volume 128, Issue 4, August 2017, Pages 675-678
Journal: Proceedings of the Geologists' Association - Volume 128, Issue 4, August 2017, Pages 675-678
نویسندگان
Stephen K. Donovan, Fiona E. Fearnhead, A.J. (Ton) de Winter,