Error Installing RDatasets

After I did this:
sudo apt-get install libxml2 libxml2-dev

– libxml2 libxml2-dev installed without complaint but neither libz nor zlib is there.
$ sudo apt-get install libz

E: Unable to locate package libz

sudo apt-get install zlib

E: Unable to locate package zlib

I tried the RDataset package install and complaints related to libxml went away.

I also tried
sudo apt-get install libz-dev
which returned…
Note, selecting ‘zlib1g-dev’ instead of ‘libz-dev’
zlib1g-dev is already the newest version (1:1.2.11.dfsg-0ubuntu2).

Could it be that the build for RDataset is hard coded for libz-dev and needs to be changed to zlib1g-dev?