A simple analysis of Reference lists of 10 PLOS ONE Paleontology papers

I wanted to see what the mean & median age cited papers in paleontology reference lists were.To this end in a simple 5 minute excercise I looked at 10 Open Access PLOS ONE paleontology papers all published in 2009 and parsed just the reference list in the main paper to see how old each of the referenced articles were. method: cut n paste reference list into text file & apply sed -n -e '/^[^(]*(\([^)]*\)).*/s//\1/p' (not quite perfect parsing but it'll do) in press references I manually converted to '2009'RESULTS:In the PLOS ONE Paleontology papers I sampled, the mean-age of cited papers was >18 years from the publication date of the citing paper, whilst the median-age of cited papers are >10 years from the publication data of the citing paper.It would be interesting to compare this data to data of other journals in other fields.