Professor of Biology, Harvard University

National Institute of Standards & Technology, Natural History Museum of the University of …

American. Mus. Nat. Hist.; Harvard Univ.; Univ. Arizona

Yale University

Professor Emeritus, Paleontology, University of Michigan

American Museum of Natural History

University of Oregon

Professor of Earth Sciences, University of Southern California

Virginia Tech

Professor of Paleobiology, University of Erlangen, Germany