Dave Polly and Rob have worked on this page.
Allen has also worked on the page!
brs revised the Cenozoic exhibit, and broke it into several pages -- 3/6/97.
Cenozoic pages updated to reflect Geological Society of America (GSA) 1999 Geologic Timescale, compiled by A.R. Palmer and J. Geissman
-- S. Rieboldt, Nov. 2002