Cross-sectional slices of the left second costal plate obtained through CT scanning of the holotype of Eochelone brabantica (specimen IRSNB R 0001) from the Lutetian (middle Eocene) of the Saint-Remy-Geest locality (Walloon Brabant, Belgium). a–c. 3D models of the ventral (a, b) and lateral (c) views digitized by photogrammetry. a1–a8. Perpendicular view of the hole along the XY plane. b1–b7. Perpendicular view of the hole along the YZ plane. c1–c4. Parallel view of the hole along the XZ plane. Scale bars: 4 cm (a, b); 2 cm (c). The arrow indicates the hypodense bone structure.