A Cenozoic CO2 Record from Marine Proxies
The figure above shows what we think is the best compilation of marine-based proxy-based CO2 reconstructions for the last 60 million years. The CO2 data can be downloaded here (zip file here), the benthic oxygen isotope data are from Zachos et al. (2008) and can be downloaded here. See the relevant pages (here) for a review of how each proxy works and for which records we haven't included (and why we have rejected certain records/proxies).
When citing this compilation please cite the individual records contained there in and the publications listed here.
For a CO2 record for the last 420 million years see this paper here.