English: Phylogenetic reconstruction of the chromopsins. The main clades and the outgroup are collapsed. The outgroup contains non-opsin GPCRs and all other opsins. The frames highlight the gluopsins, nemopsins, and astropsins as they do not have the conserved lysine. Next to each clade is shown the number of sequences within that clade. The first pie chart shows the percentage of a certain amino acid at lysine 2967.43. Red stands for lysine (K), purple stands for glutamic acid (E), orange stands for argenine (R), the other amino acids are alternatively colored dark or mid-gray so that two adjacent amino acids have different shades of gray in the pie chart. Light gray stands for a gap at this position as not all sequences have data there. The second pie chart gives the taxon composition for each clade, light green stands for craniates, dark green for cephalochordates, brown for nematodes, pale pink for annelids, dark blue for arthropods, and light blue for mollusks.