کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4749675 1360608 2014 6 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
New observations on the skeletons of the earliest bryozoans from the Fenhsiang Formation (Tremadocian, Lower Ordovician), Yichang, China
کلمات کلیدی
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فسیل شناسی
پیش نمایش صفحه اول مقاله
New observations on the skeletons of the earliest bryozoans from the Fenhsiang Formation (Tremadocian, Lower Ordovician), Yichang, China
چکیده انگلیسی

The earliest unequivocal bryozoans occurred in the Fenhsiang Formation (upper Tremadocian, Lower Ordovician) of Yichang, South China, providing important clues about the early evolution of primitive bryozoans. In this study, SEM and EDAX were used to analyze the microstructure of the walls of two bryozoan genera, Nekhorosheviella and Orbiramus, from the Fenhsiang Formation. All walls of Nekhorosheviella and endozonal walls of Orbiramus show poor preservation in thin sections, with a granular appearance reflecting extensive neomorphism, whereas exozonal walls of Orbiramus are distinctly laminated. These preservational differences may reflect skeletal chemistry, particularly the magnesium content of the calcite. Phosphatic skeletal linings were found to be distributed unevenly in the autozooecia of Nekhorosheviella, but were absent in Orbiramus.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Palaeoworld - Volume 23, Issue 1, March 2014, Pages 25–30
نویسندگان
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