Figure 7
From: Qualitative skeletal correlates of wing shape in extant birds (Aves: Neoaves)
MicroCT surfaces and slices through dorsal remigial papillae ( drp ). (a-b) Fregata (CM S13606) and (c-d) Cathartes, showing open spaces isolated from the main medullary cavity of the ulna. Cathartes specimen is embedded in plastic for histological sectioning—feather pulp cavities appear as void spaces in the slice. crp, caudal remigial papillae; 2°, pulp cavity of secondary remex.