The Last Global Extinction in the deep sea - Late Pliocene to mid-Pleistocene extinctions (Stilostomella Extinction Event)

Collaborator: Ellen Thomas (Yale University, USA)

Post-Doctoral Fellows: Shungo Kawagata, Katie Johnson; PhD student: Liesbeth van Kerckhoven
MSc students: Tanya O'Neill (Massey University, Palmerston North), Francie Geiger (University of Canterbury, Christchurch)

The last major extinction period in the deep sea occurred during the Late Pliocene to the mid-Pleistocene climate transition (MPT), just 3 million to 600,000 years ago, as the Ice Age climate cycles rapidly increased in severity and amplitude. This episode was first noted in the Atlantic Ocean 35 years ago, and has subsequently been recognised world-wide, although it has received little specific attention prior to our recent studies (since 2001). It was named the "Stilostomella extinction" after a prominent family of foraminifera that died out at this time. This last global extinction episode preferentially targeted elongate cylindrical forms, often with specialised apertural modifications (stilostomellids, pleurostomellids, some nodosariids). Our studies have shown that becoming extinct at this time were five complete families (Chrysalogoniidae, Stilostomellidae, Ellipsoidinidae, Pleurostomellidae, Glandulonodosariidae), and almost another (Plectofrondiculariidae), involving 30 genera, and 104 species (c. 25% of deep-sea foraminiferal diversity at the time).

Between 2001 and 2006, we investigating the global architecture, timing, taxonomic impact and causes of this puzzling and poorly understood extinction event.
Between 2007-2011, we investigated the Cenozoic history of the Extinction Group and the impacts of the PETM warm event and mid Miocene cooling event on them. In 2012 we published a Monograph documenting the architecture of the Last Global Extinction, the Cretaceous-Cenozoic history of the Extinction Group families and a thorough taxonomic review and atlas of the 250 species in Extinction Group families.

High-resolution studies of the late Pliocene to mid-Pleistocene record of these extinctions was undertaken in the following study areas:

a. South-west Pacific (DSDP 593, 594, ODP 1119, 1120, 1123, 1125). - Published, 2001, 2002, 2005, 2013 (with Mancin et al.).
b. North Atlantic gateway (ODP 980, 982). - published, 2005.
c. Caribbean (ODP 1000). - published, 2006, with Andre Droxler and Michelle Shearer.
d. South Atlantic-Southern Ocean (ODP 1082, 1083, 1088). - Published, 2007. MSc thesis of Tanya O'Neill.
e. Indian Ocean (ODP 722, 758). - Published, 2006, with Anil Gupta
f. North Pacific - South China Sea (ODP 1143, 1146). - Published, 2007, with Wolfgang Kuhnt
g. Equatorial Pacific (core KR9912PC4). Published, 2010
h. Mediterranean Sea (ODP 966, 975, 976) - published, 2009
i. North-east Pacific (ODP 1012) – published, 2010
j. West North Atlantic (ODP 1055) – published, 2010
k. Pleistocene stratigraphy of deep-sea ostracods (ODP 1125) - MSc thesis of Francie Geiger, 2006
l. Extinct species in Brady's Challenger Report. published, 2005.
m. Global summary. Published, 2007.

Low-resolution studies of Cenozoic record of the Extinction Group benthics in the following areas:

a.       Indian Ocean (ODP 722, 738, 744, 758, 763) – published 2010, with Ritsuo Nomura, Claudia Schroeder-Adams, Anil Gupta

b.      North Atlantic (DSDP 548, ODP 608) – published 2010, with Ellen Thomas

c.       Equatorial Pacific (DSDP 317, ODP 865) – published 2010, with Ellen Thomas

High-resolution study of Extinction Group through middle Miocene cooling event in the following area:

a.       Pacific Ocean (ODP 1143, 1236) – published 2011. Post-doc study of Katie Johnson, with Ann Holbourn.

High-resolution study of Extinction Group through PETM hot event in the following areas:

a.       Southern Ocean (DSDP 589, 590) – PhD thesis by Liesbeth van Kerckhoven, completed, 2014

b.      North Pacific Ocean (ODP 865, 1211) - PhD thesis by Liesbeth van Kerckhoven, completed, 2014

Publications