This is a pretty substantial article from a large number of authors working in a variety of taxonomic groups regarding the proper presentation of data when looking at historical patterns in paleontology and geology. This is a must read for anyone using fossils to calibrate anything.
Parham, J. F., et al. 2012. Best practices for justifying fossil calibrations. Systematic Biology. doi: 10.1093/sysbio/syr107 [open access].
A Comet Unnoticed
5 hours ago in The Astronomist