Greg Retallack, Department of Earth Sciences

Greg Retallack

Professor Emeritus
Practice Areas: Global Climate Change, Mass Extinctions, Major Evolutionary Transitions, Ancient Mars Environments, the Origin of Life

Greg Retallack is an academic expert in global climate change, mass extinctions, major evolutionary transitions, ancient Mars environments, and the origin of life. Greg studies the evolution of life on land, and in particular, the evidence of fossil soils. His past studies have explored the role of soils in ape and human evolution in Kenya, grassland evolution in North America, and dinosaur extinction in Montana.

Recent Media:
In a fierce desert, microbe ‘crusts’ show how life tamed the land (Quanta Magazine, July 12, 2023) 
A Natural Work of Art May Be Hiding Among Indian Cave Masterpieces (The New York Times, Feb. 5, 2021)
Dolly Parton Lends Her Name To A 460 Million-Year-Old Fossil Plant (Forbes, Nov 28, 2020)
Geologist helps confirm date of earliest land plants on Earth (Around the O, Nov. 3, 2020)
Geology study offers a deep-time perspective on climate (Around the O, May 13, 2020)
Ancient fossils reveal fresh clues about early life on land (Around the O, Oct. 9, 2019)
Amoeba teamed up to form world’s oldest slime mold (Futurity News, Oct. 11, 2019)
Rare Mammoth Tracks Reveal an Intimate Portrait of Herd Life (Smithsonian Magazine, Feb. 26, 2018)
U.S. geologist discovers Earth-like soils on Mars (, August 22, 2014)
'Fossilized' Martian soil hints at signs of life (GMA News Online, July 22, 2014)
VIDEO: Signs of life on Mars (University of Oregon, July 16, 2014)
Creatures of the Ediacaran (ScienceLine, March 14, 2014)
Land creatures might not have come from the sea (National Public Radio, Dec. 12, 2012)
Controversial claim puts life on land 65 million years early (Nature, Dec. 12, 2012)