ClipArt ETC
"Young bearded griffin (Gypaetus barbatus). Showing the feather-tracts or pterylae, for instance those on the breast (PT.). E., ear; P., web or propatagium; TH., thumb; PR., bases of primary feathers; S., bases of secondary feathers; B.S., bare streak without pterylae; CL., cloaca; R., bases of rectrices or tail feathers." -Thomson, 1916

Lammergeier

"Young bearded griffin (Gypaetus barbatus). Showing the feather-tracts or pterylae, for instance those…