SUMMARY AND CONCLUSIONS

We used high-resolution X-ray computed tomography scanning to prepare a digital reconstruction of the braincase of Youngina. We largely agree with the description presented by Evans (1987) of the braincase of Youngina, but we have provided new information on the shape of the stapes in Youngina, which differs from previous interpretations by Evans and other authors. We present the first 3D visualizations of the semicircular canals in Youngina, as well as offering possible implications for hearing in this important early stem-diapsid. Our reconstruction and anatomical description will prove useful in the development of new phylogenetic analyses of diapsid reptiles, and help resolve the relationships of Youngina and the other "younginiform" grade taxa within the Diapsida.