Naslov
Coastal coccolithophores and K/T boundary

Autori
Young, Jeremy R. ; Hagino, Kyoko ; Bown, Paul R. ; Godrijan, Jelena

Vrsta, podvrsta i kategorija rada
Sažeci sa skupova, sažetak, znanstveni

Izvornik
INA13 Abstract Volume / - , 2010

Skup
13th International Nannoplankton Association Conference

Mjesto i datum
Yamagata, Japan, 05.09.2010. - 10.09.2010

Vrsta sudjelovanja
Predavanje

Vrsta recenzije
Međunarodna recenzija

Ključne riječi
coccolithophores; coastal; K/T boundary; plankton

Sažetak
The catastrophic global change events which occurred at and after the Cretaceous/Palaeogene boundary event resulted in extinction of ca. 90% of the nannoflora. Equally remarkably the relatively few survivor species were almost universally rare in the preceding Late Cretaceous assemblages. Almost all the typical oceanic species appear to have gone extinct abruptly including many species and genera with long geological ranges <i>Watznaueria barnesiae, Arkhangelskiella cymbiformis Prediscosphaera cretacea</i> and <i>Cribrosphaerella ehrenbergii</i>. By contrast typical survivor species such as <i>Braarudosphaera bigelowii</i> and <i>Goniolithus fluckigera</i> were only sporadically present in typical Late Cretaceous assemblages. This pattern and analysis of the possible ecological affinities of the survivor and incoming species lead Bown (2005) to speculate that coastal adaptation may have been a key factor in allowing survival. Likewise Medlin et al. (2008) used molecular clock evidence to argue that the modern neritic coccolithophore <i>Cruciplacolithus neohelis</i> may be the direct descendant of the morphologically identical early Palaeocene species <i>Cruciplacolithus primus</i>. They further argued that the absence of any bottlenecking in the molecular phylogeny of the predominantly coastal non-calcifying <I>Chrysochromulina</i> species provided further evidence for the K/Pg extinctions primarily affecting the oceanic coccolithophores. New data from extant coastal coccolithophores collected from Totori Port in Japan and the Rovinj Marine station in Croatia combined with observations on exceptionally preserved fossil samples from Tanzania provide remarkable new support for this hypothesis. Finally, review of data from calcareous dinoflagellates and planktonic foraminifera indicate that oceanic extinctions and coastal survivorship was probably a universal pattern among calcareous plankton.

Izvorni jezik
Engleski

Znanstvena područja
Geologija

POVEZANOST RADA