کد مقاله کد نشریه سال انتشار مقاله انگلیسی نسخه تمام متن
4747757 1359932 2006 9 صفحه PDF دانلود رایگان
عنوان انگلیسی مقاله ISI
The peculiar taphonomy of the streamlined late Campanian ammonite Metaplacenticeras subtilistriatum from northern Hokkaido, Japan
موضوعات مرتبط
مهندسی و علوم پایه علوم زمین و سیارات فسیل شناسی
پیش نمایش صفحه اول مقاله
The peculiar taphonomy of the streamlined late Campanian ammonite Metaplacenticeras subtilistriatum from northern Hokkaido, Japan
چکیده انگلیسی

The peculiar taphonomy of the late Campanian ammonite Metaplacenticeras subtilistriatum is reconstructed on the basis of stratigraphic occurrence within the Hakobuchi Formation of northern Hokkaido (Japan), as well as of host rock and patterns of fragmentation. The species' taphonomy is closely linked to its streamlined, oxyconic shell with flat flanks and a smoothly tapered venter. Such shells were accumulated, together with numerous pebbles, by bottom currents (>0.25–0.5 m/s), in such a way that ventral portions of some shells fractured by collision with pebbles. Small holes and depressions in the external shell surface, presumably formed during compaction after final burial, are restricted to phragmocones. On this evidence, it is suggested that this species was nektobenthic, lived in a shallow environment (shoreface–inner shelf) where its streamlined shell allowed it to align with prevailing currents, similar to a wind vane.

ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Cretaceous Research - Volume 27, Issue 6, December 2006, Pages 863–871
نویسندگان
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