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.
Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden; Department of Sciences, Museum Victoria, GPO Box 666, Melbourne 3001, Victoria, Australia.
Alice M
AM
Clement
Department of Information Technology, Centre for Image Analysis, Uppsala University, Lägerhyddsvägen 2, 751 05 Uppsala, Sweden.
Johan
J
Nysjö
Department of Information Technology, Centre for Image Analysis, Uppsala University, Lägerhyddsvägen 2, 751 05 Uppsala, Sweden.
Robin
R
Strand
Department of Organismal Biology, Evolutionary Biology Centre, Uppsala University, Norbyvägen 18A, 752 36 Uppsala, Sweden.
Per E
PE
Ahlberg
D000818:Animals; D001921:Brain / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D005399:Fishes / Q000033:anatomy & histology*; D005580:Fossils / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D012886:Skull / Q000033:anatomy & histology* / Q000000981:diagnostic imaging; D014057:Tomography, X-Ray Computed