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About Ellen Thomas

I investigate the impact of changes in environment and climate on living organisms on various time scales, from millions of years to decades, with the common focal point of benthic foraminifera (eukaryotic unicellular organisms). Foraminifera live in salt or at least brackish water, so I concentrate on the oceans, from the deep sea up into tidal salt marshes. The deep sea is the largest habitat on Earth, supports a high diversity of organisms, but is one of the least known. I am interested in understanding the development of high-diversity deep-sea faunas through periods of major climate change and mass extinction, such as the mass extinction caused by meteorite impact at the end of the Cretaceous (65 million years ago), which did not affect benthic foraminifera significantly. I participated in Ocean Drilling Program Leg 208 in the South East Atlantic Ocean, studying causes and consequences of extreme warm climates on Earth, including the extinction of deep-sea benthic foraminifera at the end of the Paleocene (55 million years ago), linked to an early greenhouse episode. I also look at changes in deep-sea faunas during other periods of global change, such as the earliest Oligocene (~33.5 million years ago) when the Antarctic ice sheet originated, and am interested in possible links between glaciation and initiation of the AntArctic Circumpolar Current. I look into the climate swings of ice ages during the last few hundred thousands of years. Together with Joop Varekamp I work at the edge of the oceans in coastal salt marshes in Connecticut and New Jersey, trying to understand the ecology of salt marshes as well as rates of relative sea-level rise during the last 2000 years. We also cooperate in research on the changing environments and ecosystems in Long Island Sound, at time scales varying from the last 15,000 years to the time since European settlement and industrial revolution, and the eutrophication caused by human presence.


Present Research Professor in Earth & Environmental Science, Wesleyan University
Present Senior Research Associate Geology and Geophysics, Yale University

Curriculum Vitae

Research Interests

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Honors and Awards

  • 2004-2005: Distinguished Lecturer, Joint Oceanographic Institutions (
  • 1996: W. Storrs Cole Memorial Research Award, Geological Society of America: $10,000.-
  • 2008: Zachos, J., Pagani, M., Sloan, L., Thomas, E., and Billups, K., 2001: ‘Trends, Rhythms, and Aberrations in Global Climate Change 65 Ma to Present. Science, 292: 686-693’ Thomson Reuters Scientific's Essential Science Indicators identifies it as of the most highly cited papers in Geosciences.
  • 2010: elected Fellow of AAAS

Contact Information; Telephone: extension 2238; Office: Exley Science Center 459


Cretaceous-Tertiary Boundary (7)

Pleistocene-Recent (3)

Paleocene-Eocene and Greenhouse World (6)

Miocene and Monsoons (2)