Interesting details in, ‘Mycoplasma pneumoniae and Its Role as a Human Pathogen’. The picture they provide shows that ‘arrow’ like attachment organelles on M. pneumoniae.
The term “mycoplasma” (Greek; “mykes” = fungus and “plasma” = formed) emerged in the 1950s (117) and replaced the older PPLO terminology. The allusion to a fungus-like growth pattern in the name “mycoplasma” happens to describe only the growth of M. mycoides, but the term was nevertheless adopted and has persisted to this day. In the 1960s, mycoplasmas were designated members of a class named Mollicutes, which derives from Latin words meaning soft (“mollis”) and skin (“cutis”). The current taxonomic designations included in class Mollicutes comprise 4 orders, 5 families, 8 genera, and about 200 known species that have been detected in humans, vertebrate animals, arthropods, and plants. M. pneumoniae is a member of the family Mycoplasmataceae and order Mycoplasmatales.
Mycoplasmas represent the smallest self-replicating organisms, in both cellular dimensions and genome size, that are capable of cell-free existence.
Link to chart.