Charles Marshall sitting between skulls of T. rex and a giant extinct marine Mesozoic monster

Research Bio

Charles Marshall is a paleobiologist whose research seeks to understand the history of life on Earth by integrating fossil data with evolutionary theory and geologic context. His work explores macroevolutionary patterns, mass extinctions, and the processes that shape biodiversity over deep time.

Marshall is widely recognized for applying quantitative models to the fossil record to infer evolutionary rates and environmental drivers of extinction. His research has contributed to debates on the timing of the Cambrian explosion, the diversification of vertebrates, and the extinction of the dinosaurs.

An expert in evolutionary biology and paleontology, Marshall is a professor in the Departments of Integrative Biology and Earth & Planetary Science at UC Berkeley. He is Director of the UC Museum of Paleontology and a Fellow of the Paleontological Society and the Geological Society of America.

Research Expertise and Interest

paleontology

In the News

How many T. rexes were there? Billions.

How many Tyrannosaurus rexes roamed North America during the Cretaceous period? That’s a question Charles Marshall pestered his paleontologist colleagues with for years until he finally teamed up with his students to find an answer.

Featured in the Media

Please note: The views and opinions expressed in these articles are those of the authors and do not necessarily reflect the official policy or positions of UC Berkeley.
April 16, 2021
Kenneth Chang

Researchers have calculated that approximately 20,000 Tyrannosaurus Rex adults lived at any one time in North America. Charles R. Marshall, a professor of integrative biology at the University of California, Berkeley who led the research, said the work started with him wondering, when he held a T. rex fossil, how rare was that? "Were there are a million, a billion, a trillion T. rexes?" he said. "Is this one in a million, one in a billion, one in a trillion? How on earth could we know that number? We all know fossils are rare, but how rare are they? And so it really started with that question." For more on this, see our press release at Berkeley News. Stories on this topic have appeared in dozens of sources, including the Associated Press, CNN, The Guardian, USA Today, The Mercury News, LiveScience, JumpRadio, Taipei Times, Forbes, Voice of America, and The New York Post.

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Teaching

Courses taught during the three most recent terms
2026 Spring
  • Paleobiological Perspectives on Ecology and Evolution  [INTEGBI 113L]  

  • Directed Undergraduate Research  [INTEGBI 191]  

  • Supervised Internship  [INTEGBI 197]  

  • Supervised Independent Study and Research  [INTEGBI 199]  

  • Special Study for Graduate Students  [INTEGBI 296]  

  • Directed Field Studies  [INTEGBI 297]  

  • Special Study in Integrative Biology  [INTEGBI 298]  

  • Graduate Research  [INTEGBI 299]  

  • Supervised Independent Study and Research  [INTEGBI 99]  

  • Thesis Course  [INTEGBI H196A]  

  • Thesis Course  [INTEGBI H196B]  

2025 Fall
  • General Biology Lecture and Laboratory  [BIOLOGY 1B]  

  • Directed Undergraduate Research  [INTEGBI 191]  

  • Supervised Independent Study and Research  [INTEGBI 199]  

  • Special Study in Integrative Biology  [INTEGBI 298]  

  • Graduate Research  [INTEGBI 299]  

  • Thesis Course  [INTEGBI H196A]  

2025 Summer
  • Graduate Research  [INTEGBI N299]  

2025 Spring
  • Directed Undergraduate Research  [INTEGBI 191]  

  • Supervised Internship  [INTEGBI 197]  

  • Supervised Independent Study and Research  [INTEGBI 199]  

  • Research Seminar  [INTEGBI 290]  

  • Special Study for Graduate Students  [INTEGBI 296]  

  • Directed Field Studies  [INTEGBI 297]  

  • Special Study in Integrative Biology  [INTEGBI 298]  

  • Graduate Research  [INTEGBI 299]  

  • Thesis Course  [INTEGBI H196A]  

  • Thesis Course  [INTEGBI H196B]