here is some data that might be interesting to play with. it is data
on kangaroos in australia - comes from andrews and herzberg "data"
book.

the problem is that there are 3 historical skulls (housed in
different museums in europe) whose species identification got lost
somewhere along the line. so measurements were collected from 3
different species, both males and females from herds near where the
originals were collected in order to identify the historical skulls.
one complication is that kangaroo skulls keep growing throughout life
and they can be affected by diet. the historical skulls came from
kangaroos transported to europe in the late 1800s fed on a bread and
beer diet!