Topics of Research

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).  I study their assemblages, as well as trace element and isotope composition of their shells. 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 study foraminifera from the deep sea floor, using samples from the International Ocean Discovery Program. 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 have spent years, but am still working on, the early Cenozoic extreme warm climates (Paleocene through middle Eocene), specifically looking at the effects of ocean acidification and deoxygenation, and the deep-sea benthic foraminiferal extinction at the end of the Paleocene. I am also studying deep-sea benthic foraminifera during the establishment of the Antarctic ice sheet at the end of the Eocene – beginning of the Oligocene, being interested in possible links between glaciation and initiation of the AntArctic Circumpolar Current and deep-sea environments.

In addition, foraminifera are great tools to study anthropogenic eutrophication, and together with professor Joop Varekamp I am studying recent climate change, environmental pollution and acidification of Long Island Sound and Great Salt Pond (Block Island RI). We also cooperate in research on rates of sea level rise at the end of the last glacial period in Long Island Sound, and on rates of sea level rise and ecological changes in coastal salt marshes during the last 2000 years.

Foraminifera are of great interest to me, so I am working to get beautiful 3D-pictures and models as well as 3D print-files of them widely available on-line, working with people at the American Museum of Natural History (NY) and at the University of Bristol (UK). See this video for an example, or the picture for November in the 2015 Calendar by The Micropalaeontological Society.

Blog on Foraminiferal Taxonomy, UK 2012

More about me (5 things) at the AAAS site.

A narrative about the work on the foraminifera collections at the AMNH in the web series ‘Shelf Life’: Episode Six: The Tiniest Fossils. Some of the Museum’s smallest specimens hold big insights about the history of Earth’s climate.

Blog by interns at the American Museum of Natural History, Summer 2015

Career Profile, AWG

Website at Yale University, Geology & Geophysics

I am working on getting the Wesleyan Natural History collections more in the public sight, as for instance with the Glyptodon exhibit.

I retired from teaching by 1 July 2021, but am still working on research and the Wesleyan Joe Webb peoples Museum.


  • 2023: BBVA Frontiers of Knowledge Award in Climate Change (shared with J. Zachos)
  • 2021: Wesleyan Prize for Excellence in Research
  • 2020: Joseph A Cushman Award for Excellence in Foraminiferal Research
  • 2016: Brady Medal, The Micropalaeontological Society
  • 2013: Association for Women Geoscientists Professional Excellence Award (Academia)
  • 2013: Leverhulme Visiting Professor, Bristol University, UK
  • 2012: Maurice Ewing Medal, AGU/ONR (see award ceremony)
  • 2012: Fellow of AGU
  • 2011: Fellow of AAAS
  • 2007: Exceptional Reviewer, Geology
  • 2004-2005: JOI Distinguished Lecturer
  • 1996: W. Storrs Cole Award
  • 1995: Excellence in reviewing, Paleoceanography

Editorial Activity:

  • Editor-in-Chief of Paleoceanography, 2015-2019
  • Editor of Geology, 2012-2015
  • Editor of Marine Micropaleontology, 2003-2010
  • Editorial Boards  Palaeogeography, Palaeoclimatology, Palaeoecology, and Marine Micropaleontology
  • Editorial Board Paleoceanography, 1996-2002; Geology 2000-2002

Publications Ellen Thomas