Figure 4. Lens compaction as a function of age in the crocodile, rat, cow and chicken, kangaroo and tree shrew. Data for related species were grouped and colours were assigned to the groups – bats (black), birds (light blue), carnivores (red), ectothermal species (reptiles, amphibians, fish, yellow with black outline), lagomorphs (purple), marsupials (dark green), primates (light green), rodents (orange with black outline), tree shrew. (light green with black outline) and ungulates (dark blue).