Did the Late Paleocene thermal maximum affect the evolution of larger foraminifers? Evidence from calcareous plankton of the Campo Section (Pyrenees, Spain)

The Paleocene-Eocene Thermal Maximum: New Data on Microfossil Turnover at the Zumaia Section, Spain

“…Planktic foraminifera of the Zumaia section had already been examined by several previous authors (Hillebrandt, 1965;Canudo & Molina, 1992;Arenillas & Molina, 1995;Canudo et al, 1995;Pardo et al, 1996;Schmitz et al, 1997;Arenillas &Orue-Etxebarria et al, 2001). …”

“…In fact, this event had an important biotic impact on both land and marine organisms, affecting groups as diverse as land mammals (e.g. Wood et al, 1941;Clyde & Gingerich, 1998), deepwater benthic foraminifers, (Thomas, 1990;Thomas & Shackleton, 1996;Speijer et al, 1996), benthic communities of middle and outer neritic marine settings, (Speijer 1994;Speijer et al, 1996;Speijer and Schmitz, 2000), and shallow marine larger foraminifera fauna (Orue-Etxebarria et al, 2001;Pujalte et al, 2003).…”

“…Even after a very careful examination of all samples above the CIE onset, we have not found any specimens of Acarinina sibaiyaensis, Morozovella allisonensis and M. africana, species restricted to the PETM which were described by Kelly et al (1996) and found by Lu et al (1998) throughout the Tethys realm. These species have neither been found in other sections of the Pyrenees Orue-Etxebarria et al, 2001 andPujalte et al, 2003). They may be characteristic of tropical latitudes (Kelly et al, 1996), or that M. allisonensis and A. sibaiyaensis are ecophenotypical variants (Kelly et al 1998).…”

Circum-Tethyan carbonate platform evolution during the Palaeogene: the Prebetic platform as a test for climatically controlled facies shifts

“…Scheibner and Speijer (2008a) show that the global warming during the early Palaeogene caused a Tethyan-wide massive decline in coral reefs and a coeval shift to larger carbonate platforms dominated by benthic foraminifera. The authors define the circum-Tethyan platform stages and link the evolutionary impact of the larger foraminifera turnover (Orue-Etxebarria et al 2001) at the Palaeocene-Eocene boundary directly to the Palaeocene-Eocene thermal maximum. Nebelsick et al (2005) summarise changes in specific carbonate facies types in the circum-alpine area during the Middle Eocene to Oligocene and introduce the concept of facies dynamics.…”

Effects of ocean acidification on calcification of symbiont-bearing reef foraminifers

“…Atmospheric CO 2 concentrations were more than 1000 ppm for the Paleocene and early Eocene, then declined into the middle Eocene (Pearson and Palmer, 2000;Demicco et al, 2003). Although large benthic foraminifers diversified following the terminal Cretaceous extinctions, a reduction of the genetic diversity and a simultaneous diversification at species level and a considerable increase of their shell size and adult dimorphism, which are referred to as a larger foraminiferal turnover, appears to have been coeval with the Late Paleocene Thermal Maximum (Orue-Etxebarria et al, 2001), when atmospheric CO 2 exceeded over 2000 ppm (Pearson and Palmer, 2000;Demicco et al, 2003). During the middle Eocene, when atmospheric CO 2 levels were similar to or higher than present (Pearson and Palmer, 1999), large benthic foraminifers with hyaline shells such as Nummulites extremely diversified and dominated tropical, shallow-water carbonate environments (Hallock et al, 1991).…”