This chart by Mike Sleigh in 1988 was one of the first efforts to map out the rootlet structures for a wide diversity of protists.

To develop this chart, Sleigh has to try to work out which basal bodies in different lineages were homologous. This was made additionally complex because basal bodies have a life cycle - they go through a process of maturing in which in one cell cycle a basal body may be 'adolescent' but after another cell division it may become the mature basal body. As this maturation process occurs, the associations with other cell components may change. Consequently, the task of working out homologies had to ensure that comparisons were being made among the mature basal bodies.

In addition, it was necessary to align the orientations within the cell.

A comparison of the kinetoplastid and euglenid flagellar apparatus confirmed Sleigh's 1973 arguments of the close affinity of these lineages, an affinity that was corroborated by comparative sequence studies.

With the exception of the proteromonads, the top row combined 15 years later in the concept of the Excavata.