Fig. 4

RUNX2 repeat length vs facial length ratio in marsupialsTable (left panel) showing the number of Q and A repeats, QA ratio and facial length (FL) ratio across the species examined, grouped into specific orders. The RUNX2 repeat ratio shows little to no correlation with facial length ratio across marsupials at multiple taxonomic levels. Marsupials possess a highly-conserved repeat length of 17Q:22A, especially within the australidelphians. The American marsupials displayed a slightly shorter repeat and the marsupial mole possesses a greatly extended glutamine repeat. Graph (right panel) showing facial length ratios plotted against QA ratio for all species shown in the table. Coloured dots indicate specific orders as shown in the table on left. When compared to the various spectra of facial length ratios there was no clear correlation (R² = 0.09). Skulls from the Eastern barred bandicoot (top), Virginian opossum (middle) and koala (bottom) are shown to demonstrate variation in craniofacial morphology