Fig. 7. More still views of the 3D reconstruction.

The head models with positional indicators of anterior (ant), lateral (lat), and superior (sup) in the top right corners indicate the angle of the still views on the 3D construction. The corresponding time points in Supplementary Movie 1 are indicated next to the clapperboards, as minutes and seconds. Images were taken in ParaView. Slicing the 3D reconstruction virtually along a parasagittal plane through the left nasal cavity exposes the nasal epithelium (orange) lining the septal aspect (a) and the lateral aspect (b) of the left nasal cavity. The distribution of OSNs (white) is irregular and the borders of the area occupied by OSNs are serrated. At the anterior face of the specimen, the luminal surface of the nasal epithelium of the left and right nasal cavities (white dotted lines) was physically cut. The curvature of the superior turbinate (black dotted line; b) is visible in the posterior aspect above a hole in the specimen. The perpendicular plate of the ethmoid bone (septum, black dashed line; a) lies in a midsaggital plane. Fila olfactoria (arrows) traverse the cribriform plate (crib). The accessory olfactory artery (arrowhead) is partially visible. High-magnification views of the dashed rectangles in (b) show posterior fila olfactoria (c) and anterior fila olfactoria (d) (arrows) traversing the cribriform plate through foramina (white dashed lines) toward the olfactory bulb (yellow). Parasagittal still views of the septal aspect (e) and lateral aspect (f) of the left nasal cavity highlight the irregular topography of OSNs within the nasal epithelium. In the lateral aspect (f), OSNs do not extend below the curvature of the superior turbinate (black dotted line). High-magnification views of the dashed rectangles in (f) illustrate the difference in OSN density posteriorly (g, dense) compared to anteriorly (h, less dense).