Figure 2:

Mollusk consensus diagram based on superimposing the ten mollusk sequences onto the Katharina tunicata large subunit ribosomal RNA secondary structure diagram. Positions with a nucleotide in all ten sequences are shown in one of four categories. Uppercase letters are for positions that are conserved in all ten sequences, lowercase letters are conserved in 9/10 sequences, solid circles are for positions conserved in 8/10 sequences, and open circles are for positions conserved in less than 8/10 sequences. Positions with at least one deletion are shown with arcs; the arc labels indicate the upper and lower number of nucleotides known to exist within the variable region. We designated arcs with a range of 4 or more nucleotides as ambiguous (one exception is the arc with a range of 3-25 nt in Domain V largely due to the absence of this region in stylommatophoran gastropods).