...besause they are to huge or in 3D.
The first three:
I always want to draw a dragon skeleton in life size and here it is: a Brevibrachius viridis, 1,5m long with an wingspan of 45cm.
The smaller drawing of the whole skeleton (pic 1) shows how I manage to reproduce the proportion of the original sketch (which is just 5cm long). beside references of real animals I used graphics I already made, like the Indoraptor skeleton, the Brevibrachius skull or the wing construction of modern and extinct draconiformes.
On pic 4 you see some objects I made already for the next Rundgang exhibtion. Inter alia a cladogram of snails from Pyrungata (just a few species which are known from Spiderland)
Pic 5 shows dragon eggs for the big Umgragrus nest you maybe know from the photos of my last exhibition. There are also koproliths and parts of the last meal.
6 and 7 present the prototype of an souvenier idea I had a week ago...
edit: here another object [link]