Fig. 3 in The origins of the cochlea and impedance matching hearing in synapsids

Fig. 3. Distribution of cavities in the otic region of the non-mammalian synapsid Pristerodon mackayi Huxley, 1868 (MB.R.985) from the Late Permian of Biesjespoort, South Africa. Note the concentration of a number of large cavities (brown) around the inner ears, which are connected to each other. The neurocranium is shown transparent.