* 2023-01-dated.nw: dated tree
* coaltree.tre: coal unit tree
* preparesh-date-tree.sh: compare these two trees using newick utilities and create the following two files
* time-len-vs-depth.txt: shows depth of each branch
* coal-vs-time.txt: shows comparison of coal unit and time
* annotations.txt: shows clade membership for all taxa
* Fig5b.R: draw figure

