Data from: Brain – endocast relationship in the Australian lungfish, Neoceratodus forsteri, elucidated from tomographic data (Sarcopterygii: Dipnoi)

Although the brains of the three extant lungfish genera have been previously described, the spatial relationship between the brain and the neurocranium has never before been fully described nor quantified. Through the application of virtual microtomography (μCT) and 3D rendering software, we describe aspects of the gross anatomy of the brain and labyrinth region in the Australian lungfish, Neoceratodus forsteri and compare this to previous accounts. Unexpected characters in this specimen include short olfactory peduncles connecting the olfactory bulbs to the telencephalon, and an oblong telencephalon. Furthermore, we illustrate the endocast (the mould of the internal space of the neurocranial cavity) of Neoceratodus, also describing and quantifying the brain-endocast relationship in a lungfish for the first time. Overall, the brain of the Australian lungfish closely matches the size and shape of the endocast cavity housing it, filling more than four fifths of the total volume. The forebrain and labyrinth regions of the brain correspond very well to the endocast morphology, while the midbrain and hindbrain do not fit so closely. Our results cast light on the gross neural and endocast anatomy in lungfishes, and are likely to have particular significance for palaeoneurologists studying fossil taxa.Supplementary Information 1: Surface mesh distance scriptThe script surf_dist.py computes the surface-to-surface distance between two aligned STL models and displays the result as color-coded distance maps. It also computes the mean absolute distance (MAD), the root-mean square (RMS) distance, and the max absolute (Hausdorff) distance between the models and writes the resulting distance values to a text file.surf_dist.zipSupplementary Information 2: Surface mesh distance animationSurface mesh distance animation, showing Endocast, Brain, Overlay, Signed Distance Map and Unsigned Distance Map of the Australian lungfish, Neoceratodus.S2_movie.m4