English: Phylogenetic reconstruction of the tetraopsins. The main clades and the outgroup are collapsed. The outgroup contains non-opsin GPCRs and all other opsins. The frame highlights the chromopsins. 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 296^7.43. Red stands for lysine (K), purple stands for glutamic acid (E), 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, mid green for echinoderms, dark blue for arthropods, and light blue for mollusks. The support values are given as pie charts. They are from right to left SH-aLRT/aBayes/UFBoot. Splits are considered supported when SH-aLRT ≥ 80%, aBayes ≥ 0.95, and UFBoot ≥ 95%. If a support value is above its threshold the pie chart is black otherwise gray.