Broeckina gassoensis sp. nov., a larger foraminiferal index fossil for the middle Coniacian shallow-water deposits of the Pyrenean Basin (NE Spain)
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- 作者：Esmeralda Caus ; Mariano Parente ; Vicent Vicedo ; Gianluca Frijia ; Ricard Mart铆nez
- 关键词：Larger Foraminifera ; Biostratigraphy ; Strontium isotope stratigraphy ; Coniacian ; Pyrenees ; Spain
- 刊名：Cretaceous Research
- 出版年：October, 2013
- 年：2013
- 卷：45
- 期：Complete
- 页码：76-90
- 全文大小：9304 K
文摘
The Upper Cretaceous shallow-water carbonates of the Pyrenean Basin (NE Spain) host rich and diverse larger foraminiferal associations which witness the recovery of this group of protozoans after the dramatic extinction of the Cenomanian-Turonian boundary interval. In this paper a new, large discoidal porcelaneous foraminifer, Broeckina gassoensis sp. nov., is described from the middle Coniacian shallow-water deposits of the Collada Gass贸 Formation, in the B贸ixols Thrust Sheet. This is the first complex porcelaneous larger foraminifer of the Late Cretaceous global community maturation cycle recorded in the Pyrenean bioprovince. It differs from the late Santonian-early Campanian B.聽dufrenoyi for its smaller size in A and B generations and the less developed endoskeleton, which shows short septula. Broeckina gassoensis sp. nov. has been widely employed as a stratigraphic marker in the regional geological literature, under the name of 鈥?em>Broeckina鈥? but its age was so far controversial. Its middle Coniacian age (lowermost part of the Peroniceras tridorsatum ammonite zone), established in this paper by strontium isotope stratigraphy, indicates that it took about 5聽My after the Cenomanian-Turonian boundary crisis to re-evolve the complex test architecture of larger foraminifera, which is functional to their relation with photosymbiotic algae and K-strategy.