Editing Coccolithophore (section)

===Impact on microfossil record===
{{See also|Protists in the fossil record}}

Coccolith fossils are prominent and valuable [[Microfossil#Calcareous|calcareous]] [[microfossil]]s. They are the largest global source of biogenic calcium carbonate, and significantly contribute to the global [[carbon cycle]].<ref>{{cite journal | last1 = Taylor | first1 = A.R. | last2 = Chrachri | first2 = A. | last3 = Wheeler | first3 = G. | last4 = Goddard | first4 = H. | last5 = Brownlee | first5 = C. | year = 2011 | title = A voltage-gated H<sup>+</sup> channel underlying pH homeostasis in calcifying coccolithophores | journal = PLOS Biology | volume = 9 | issue = 6| page = e1001085 | doi = 10.1371/journal.pbio.1001085 | pmid = 21713028 | pmc = 3119654 | doi-access = free }}</ref> They are the main constituent of chalk deposits such as the [[white cliffs of Dover]].

Of particular interest are fossils dating back to the [[Palaeocene-Eocene Thermal Maximum]] 55 million years ago.  This period is thought to correspond most directly to the current levels of {{CO2}} in the ocean.<ref name=Self-Trail2012>{{citation |journal=Marine Micropaleontology |volume=92–93 |year=2012 |pages=61–80 |title=Calcareous Nannofossil Assemblage Changes Across the Paleocene-Eocene Thermal Maximum: Evidence from a Shelf Setting |first1=J.M. |last1=Self-Trail |doi=10.1016/j.marmicro.2012.05.003 |display-authors=1 |last2=Watkins |first2=David K. |last3=Wandless |first3=Gregory A. |bibcode=2012MarMP..92...61S |url=http://digitalcommons.unl.edu/cgi/viewcontent.cgi?article=1466&context=geosciencefacpub }}</ref>  Finally, field evidence of coccolithophore fossils in rock were used to show that the deep-sea fossil record bears a [[megabias|rock record bias]] similar to the one that is widely accepted to affect the land-based [[fossil record]].<ref name=Lloyd2011>{{citation |journal=Geological Society, London, Special Publications |volume=358 |issue=1 |year=2011 |pages=167–177 |title=Quantifying the deep-sea rock and fossil record bias using coccolithophores |first=G.T. |last=Lloyd |doi=10.1144/sp358.11 |display-authors=etal  |bibcode = 2011GSLSP.358..167L |s2cid=129049029 }}</ref>