کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
4735053 | 1640649 | 2015 | 6 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
A 'British' Silurian crinoid from Quinn Point, New Brunswick, eastern Canada
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موضوعات مرتبط
مهندسی و علوم پایه
علوم زمین و سیارات
زمین شناسی
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چکیده انگلیسی
Crinoids are common fossils, yet complete specimens are rare. Diverse plates from the crinoid endoskeleton may be preserved, but the columnals from the stem are the most common. Even if not distinct enough to assign to a known group, they may be classified within columnal morphotaxa. Currently, identification of distinctive columnals is adding diversity to the Silurian biota. Lanxocolumnus (col.) chaleurensis sp. nov. is a heteromorphic crinoid column from the upper Llandovery (Telychian) of Quinn Point, Chaleur Bay, New Brunswick, eastern Canada. It has large and distinctive nodals and high-order internodals, with smooth and discoid epifacets. The articular facets are sunken and nodals(?) have a unique feature, a circular pseudolumen into which a small internodal lacking an epifacet may fit. The lumen/axial canal sensu stricto is narrow, central and rounded to (commonly) pentastellate. This Canadian species is closely related to Lanxocolumnus (col.) geoffnewalli (Fearnhead and Donovan) comb. nov. from Shropshire, England. This is a further example of a crinoid taxon that migrated from Laurentia to Avalonia as the Iapetus Ocean closed.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Proceedings of the Geologists' Association - Volume 126, Issue 2, April 2015, Pages 226-231
Journal: Proceedings of the Geologists' Association - Volume 126, Issue 2, April 2015, Pages 226-231
نویسندگان
Stephen K. Donovan, David G. Keighley,