A close encounter of the first kind, according to his taxonomy, is simply seeing a UFO.
References to works dealing with the taxonomy and geographical distribution of scorpions are given at the end of this article (28).
He stressed that no-one has produced a full taxonomy for a firm yet !
When trying to create a taxonomy of emoticons, the easiest method is to go with the categories of emotions that the instant message smileys are designed to convey.
His activity was by no means confined to palaeobotany, but extended into all branches of botany, more particularly anatomy and phanerogamic taxonomy.